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Keston K170 Installation Manual

1. the pump from damage Y Strainer will The boiler guarantee collect any loose does not cover heat debris in the piping exchanger failure due to debris abrasion within the system Pump Selection The Keston boilers have low water content heat exchangers with a high resistance to flow when compared with cast iron heat exchanger boilers As a result selection of the correct pump is essential in order to avoid localised boiling within the heat exchanger The selected pump must be capable of maintaining the required flow rate for the boiler against the pressure losses contributed by the boiler Stic Pressure The Keston 170 condensing boiler offers a hydraulic resistance of 4 2m 13 75ft water at the required flow rate of 60 l m 13 2 gpm If a single pump is to be used for the entire installation the Water Flow L min boiler resistance must be added to the pressure loss caused by the rest of the Figure 2 7 7 Pressure Loss Graph Installation amp Servicing Instructions Page 10 WD51 2 1997 Chapter 2 Boiler Connections The Keston 170 Condensing Boiler system and a pump selected that is capable of meeting the flow rate required at the total pressure loss generated by the boiler and the rest of the system The selected pump must comply with BS 1394 It is important to note that the minimum flow rate must be maintained whenever the boiler is firing
2. Keston Figure 2 8 2 Flue amp Air Maximum Length Example Horizontal flue outlet pipework MUST slope at least 5 degrees 80 mm per metre run downwards towards the boiler Pipework can be vertical Only swept elbows can be used Air inlet pipework can be truly horizontal or vertical or sloping in a downward direction towards the boiler but in this case rain etc must be prevented from entering the pipe There must be no troughs in any of the pipework whether it be air inlet or flue outlet If a 80 mm per meter slope is not possible contact Keston Boilers Technical Department for further guidance Due the low temperature of the flue gases further condensate um Figure 2 8 3 will form within the flue system Aa Condensate Drain Drain points with suitable Point Example traps must therefore be incorporated within the flue system at the base of vertical flue sections in excess of 2m These additional condensate drains must be run to discharge as detailed in section 2 11 Such drain points can be formed using standard muPVC fittings Refer to the example in Figure 2 8 3 ToTeniral To Boiler 2 8 4 Terminations 50mm Tee Fitting Air inlet terminals must be facing upwards and positioned to ensure only fresh air is drawn into the boiler The air terminal must be located outside of the building Drawing of combustion air directly from a ventilated boiler room will invalidate the heat
3. 5 1 5 2 5 3 5 4 5 5 5 6 5 7 6 1 6 2 7 1 7 2 7 3 7 4 7 5 7 6 7 7 7 8 7 9 7 10 7 11 7 12 7 13 7 14 7 15 BENCHMARK INITIATIVE Timing The Gas Meter Handing Over To The User FAULT FINDING Electrical Control Sequence Fault Finding Flow Chart Continuity Checking Functional Flow Wiring Diagram Electrical Wiring Diagram Illustrated Wiring Diagram Exploded Assembly Diagrams SERVICING Pre Service Checks Recommended Routine Service REPLACEMENT OF PARTS General Precautions Access Electrical Gas Orifice Spark Ignition Flame Detection Electrode Burner Head amp Burner Heat Exchanger Air Screen Condensate Trap Pressure Gauge Sight Glass HT Ignition Lead Air Vent Air Orifice SPARE PARTS LISTINGS benchmea 4 part of the industry wide Benchmark Initiative all Keston 170 boilers now include a Benchmark Installation Commissioning and Service Record Log Book Please read this carefully and complete all sections relevant to the appliance installation The details of the Log Book will be required in the event of and warranty work being required There is also a section to be completed after each regular service visit The completed Log Book should be left with the customer CORGI CONTACT INFORMATION The boiler should be installed and serviced only by CORGI registered operatives All CORGI registered Installers carry a CORGI ID cad and have a registration number Both should be r
4. Air Press Switch Tridelta 56717 1428 Weight Empty 61 kg 134 Ibs Filter Keston Filter Data Badge Posn Right Hand Panel Inside Case Gas Supply 0 75 inch BSPT Male Connection 22mm to gas cock Water Content 7 0 litres Installation amp Servicing Instructions Page 3 2 1 2 2 2 3 WD51 2 1997 Chapter 2 Boiler Connections ee 2 BOILER LOCATION DIMENSIONS AND MINIMUM CLEARANCES The boiler must be installed in minimum clearances shown to allow subsequent servicing and safe operation SERVICE CONNECTIONS Gas water air and flue pipe condensation and electrical connections are as shown Gas 7 0 5 inch BSP male Flow Return 35 mm copper POSITION The Keston is not suitable for external installation The boiler may be installed in any room or internal space although particular attention is drawn to the requirements of the current IEE Wiring Regulations and in Scotland the electrical provisions of the Building Regulations applicable in Scotland with respect to the installation of the boiler in a room or internal space containing a bath or shower The Keston 170 Condensing Boiler All dimensions in mm Figure 2 12 Dimensions Flue Flow Air Intake Return 254 Figure 2 11 Minimum Clearances All dimensions in mm Where a room sealed 500 gt appliance is installed a 35 lt gt 22 EET x L 65 o 244
5. if in any doubt to consider the use of sealed systems where possible Installation amp Servicing Instructions Page 7 WD51 2 1997 Chapter 2 Boiler Connections The Keston 170 Condensing Boiler Expansion oe Pe dl Minimum 9ft Height Boiler T Minimum Keston Vae X Cylinder xz L S gt Valve Strainer ATLAS 2X Valve Figure2 7 1 Open Vented System Diagram 2 7 2 Sealed Systems Sealed systems must be designed in accordance with BS 5449 and BS 7074 Pt1 A typical sealed system is shown in Figure 2 7 2 It must include i A safety valve fitted on the flow adjacent to the boiler It must be non adjustable and preset to 3 bar A drain pipe must be attached at least as big as the valve connection and routed to drain in any area not hazardous nor where it may be subject to freezing ii An expansion vessel complying with BS 4814 and sized in accordance with the requirements of BS 5449 and BS 7074 Pt 1 The vessel must be positioned on the inlet to the pump iii A filling point in accordance with local water authority requirements iv A method of system make up automatic or manual in accordance with local water authority requirements v There must be no permanent connection of mains water to the boiler system vi The installation must be designed to work with flow temperatures of up to 110 C Installation amp Servicing Instructions Page 8 WD51 2 1997 Chapter 2 Boi
6. normally need re adjustment unless the unit has also been converted to LPG as Burner pressure part of the installation If the reading is Adjustment incorrect then check such factors as soundness of the air and flue pipe joints Burner pressure and the gas inlet pressure 20 mbar test nipple gt required If all joints are sound the gas inlet pressure is satisfactory remove the brass dust cap covering the burner pressure adjustment screw on the gas valve See fig 4 7 Set the gas pressure to the required value as stated in table 4 7 by turning the exposed burner pressure adjustment screw clockwise will increase burner pressure anti clockwise will decrease burner pressure This will ensure that combustion is good enough to allow combustion fine tuning to take place Replace the brass dust cap to cover the burner pressure adjustment screw TIMING THE GAS METER NATURAL GAS After the boiler has been started and with no other appliances using gas time the gas meter to be certain that the unit is running at the proper gas input Determine the cubic feet of gas passing through the meter and determine the input in Btu per hour Input must be within plus or minus 3 of the rated input Time in seconds the time taken to pass 2 cubic feet of gas through the meter ie one revolution of a 2 cu ft dial or 0 1 cubic metres if the meter is of the new metric digital type The Keston 170 when correctly set should take 39 8 se
7. 6 5 6 ILLUSTRATED WIRING DIAGRAM ILLUSTRATED WIRING DIAGRAM Flow Overheat Stat Thermal Fuse RAM Boiler Stat 4 Control 7W 930R Low Water Pressure Switch Gas Low Pressure Switch 2 Gas Valve Ignition Electrode gt Flue Overheat Stat Blower Installation amp Servicing Instructions Page 32 WD51 2 1997 Chapter 5 Fault Finding The Keston 170 Condensing Boiler 5 7 Exploded Assembly Diagrams 5 7 1 Boiler Controls Asembly SCREW Oficwimon 010 04 4 01 00 0 RAM 04 4 01 00 56 SCREW 04 1 00 84 0 2 2 GNTON PICO 04 4 11 00 d RAM 04 4 11 00 K170 17 4 00 00 0 58 TR2 THERMOSTAI 17 4 11 00 0 Y BOILER CONTROLS FUSE ISOLATOR 04 4 20 00 0 RELAY SOCKE T Lane RELAY 2317403000 05 RELAY CLAMH 17 4 00 02 0 25 SCREW 17 4 00 01 0 n 09 AIR PRESSURE SWITCH 04 4 04 00 13 SCREW 04 1 00 40 0 TERMINAL BLOCK 62 RAM 13 4 10 00 2 TERMINAL BLOC l 11 04 4 05 00 0 TERMINAL BLOC L1OQ BASE LABE 13 4 00 03 SCREW 60680707 MAINS 44 SUPRESSOR Ful 04 4 02 00 13 SECTION Fy NEON BULA L J04 4 12 00 0 13 ON OFF SWIC 04 4 06 00 0 4 6 GAUGE 9 04 4 09 00 0 14 GREEN LAMA gt 27104 4 07 00 0 Installation amp Servicing Instructions Page 33 WD51 2 1997 Chapter 5
8. ignition lead Ensure the flanged gas air supply joint is air tight Turn on the electrical supply to the boiler and allow the boiler to reach operating temperature levels Visually inspect the burner through the glass spy hole at the burner head a small mirror will prove useful Recheck the burner pressure by following the procedure detailed in Section 4 7 Remove the combustion test point plug from the flue pipe This is situated around 150mm 6ins from the bottom of the flue elbow at its connection to the heat exchanger Using an approved combustion tester sample the flue products via the combustion test point levels of between 8 2 and 8 9 for natural gas should be observed If such levels are not observed tune the combustion as described in Chapter 4 Commissioning Also check the gas flow as detailed in Sections 4 8 and 4 9 Replace the combustion test point plug Check all joints for soundness up to the gas burner Installation amp Servicing Instructions Page 40 WD51 2 1997 Chapter 7 Replacement Of Parts The Keston 170 Condensing Boilers ee INDEX 7 0 7 1 7 2 7 3 7 4 7 5 7 6 7 7 7 8 7 9 7 10 7 11 7 12 7 13 7 14 7 REPLACEMENT OF PARTS GENERAL PRECAUTIONS ACCESS PROCEDURES GENERAL ELECTRICAL 7 4 1 7 4 2 7 4 8 7 4 4 7 4 5 7 4 6 7 4 7 7 4 8 7 4 9 7 4 10 ON OFF SWITCH BOILER THERMOSTAT NEONS FLOW OVERHEAT FLOW HIGH LIMIT amp FLUE PROTECTION THERM
9. in any doubt renew the filter element Remove the burner head Section 7 7 and inspect the burner appearance Black markings or other discolourations on the gauze indicate too much gas or a lack of air possibly due to a blocked air filter Any breakages or damage to the burner mesh indicate the burner must be replaced If necessary either due to discolouration or a high pressure differential between points A amp B in the pre service checks clean the burner with a mild household detergent and rinse under a hot running tap Installation amp Servicing Instructions Page 39 WD51 2 1997 Chapter 6 Servicing The Keston 170 Condensing Boiler lt d If necessary either from visual inspection or a high pressure differential between points B amp C in the pre service checks clean the heat exchanger using a suitable stiff plastic bristle brush vacuum out any large particles and flush the heat exchanger with fresh water until the water flowing from the condensate drain is clear When brushing the heat exchanger take care not to damage the condensing plug in the lower half of the heat exchanger Remove the condensate trap Section 7 10 and clean by flushing through with clean running water Check the electrode mounted on the burner head If the point is damaged or burnt replace it Check that the spark gap measures 4 mm Replace the burner head renewing the gasket if necessary and reconnect the gas air supply and the
10. of cavity walls must be made good AIR SUPPLY The Keston is a room sealed appliance and therefore does not require purpose provided ventilation for combustion air COMPARTMENT INSTALLATION The casing temperature of the Keston 170 is very low Due to this fact no compartment ventillation is required for cooling purposes CONDENSATE DRAINAGE Being a condensing boiler the Keston is fitted with a condensate trap at the base of the heat exchanger and flue assembly with facility to connect to a drain point underneath the appliance Use only plastic piping and do not reduce below 15mm internal diameter within the dwelling Condensate should preferably be drained into the sanitary waste system or alternatively the rainwater system of the property Termination of the pipe must be either at a branch or stack internal to the house or externally at an open gully Alternatively discharge into a purpose made condensate soakaway can be considered Existing or purpose built drains must use suitable corrosion resistant material as condensate is mildly acidic A minimum slope downwards towards the drain of 1 in 20 is essential Freezing of the termination and pipework must be prevented Any drainage pipes outside the property must be at least 32 mm inside diameter RADIANT FLOOR HEATING The low operating temperatures of this type of system lead to very good operating efficiencies In fact under floor heating can produce in excess of 9
11. system must be so arranged that there shall always be a minimum flow of 13 2 gpm 60 litres min when the boiler is firing This can be via a specially installed by pass arrangement Copper tubing to BS 2871 Part 1 is recommended Jointing should be either with capillary threaded or compression fittings Pipes should have a gradient to ensure air is passed easily to vent points and water flows readily to drain points Draining taps must be located in accessible positions which permit the draining of the boiler and hot water storage vessel Draining taps should be at least 22 mm in nominal size and be in accordance with BS 2879 AIR VENT POINTS These must be fitted at all high points where air will naturally collect and must be sited to allow complete draining of the system Open Vented Systems A typical system is shown in Figure 2 7 1 which includes a combined feed and vent Note there must be no valve between the boiler flow and the open vent Note that the minimum static head required is 9 ft at the boiler flow pipe If the cold feed vent is not brought to the flow pipe as shown then the pressure loss across the heat exchanger may have to be taken into account when estimating the static pressure Although suitable for open vented systems with combined feed and vent arrangements the Keston is a low water content boiler As such any air entrainement within the system water will produce boiler kettling It is therefore recommended
12. that the air inlet and exhaust pipe outlets are at least 500mm apart Check tightness of all connections in the boiler before firing Ensure that the terminals supplied are fitted to both the exhaust and air inlet pipes The system must be free from air before firing The pump must always run when the boiler is firing Gravity circuits are not allowed If TRV s are installed on radiators ensure that a bypass is installed to maintain required flow
13. 0 58 4 Installation amp Servicing Instructions Page 34 WD51 2 1997 Chapter 5 Fault Finding The Keston 170 Condensing Boiler 5 7 3 Air Gas Assembly AIR GAS ASSEMBLY K170 17 3 00 00 0 TT ERE ap g LOW GAS ur 1 0 pressure suc 5 04 3 09 00 0 91 JREGULATOR GAS VAN 04 3 07 00 0 IR 0 92 AIR HOSE CLAM 17 3 00 07 0 AIR INLET 85 20 CONNECT 17 3 00 02 GAS INLET 93 FLEXIBLE TUB 17 3 07 00 5 emi C MAIN SOLENOID 149 04 3 07 01 0 Af CONNECTOR BLOC 150 04 3 07 02 0 n i 1 H AIR ADJ SCRE 103 1 30000 84 AIR ORIFFICE SCRE 04 3 00 40 0 em SEO SECONDARY SUNI aE 157f04 3 07 03 0 31017 3 00 01 0 N 17 3 00 01 1 e 901100 05 85 MET ose SS GASKET 17 3 00 08 0 ex 88 2 00041 NUT 632 ARNOLD P 96 57500090 89 MANIFOLD PLUG 17 3 00 05 GAS ORIFICE 17 3 00 03 0 Ng 17 3 00 03 1 LPG 98 HIGH PRESS TUB 04 3 00 32 0 8 AIR GAS 82 FLEXIBLE TUB 4 17 3 05 00 97 ILOW PRESS TUB 04 3 00 31 0 Za Beso V7 CEE N SCREW MN 1 5 5 04 1 00 81 0 Sa 52 08 2 0029 0 i ep Ere ed 2 AIR GAS 04 1 00 38 0 83MANIFOLD 17 3 06 00 0 DE 04 3 00 16 0 GASKET Ti Pn CAPACITOR BLOWER BLOWER 80 RUBBER ISOLATOF 04 3 04 00 0 SCREW 9
14. 1 Installation amp Servicing Instructions Page 35 WD51 2 1997 Chapter 5 Fault FindingThe Keston 170 Condensing Boiler 5 7 4 Casing Assembly 13 14 00 41 0 174 00010 CASING ASSEMBLY K170 17 1 00 00 0 56mm GROMMET 17 1 00 04 0 25 EXHAUST FLUE 04 1 00 52 0 TOP COVER 24 AIR INLET 17 1 04 00 0 04 1 00 51 0 NEG PR ADAPT 36 04 1 00 62 0 21 35mm GROMMET 17 1 00 05 0 FLOW LABEL 26 04 1 00 53 1 oer WARNING LABE 28 04 1 00 55 0 3 EXHAUST TERMIN 17 1 16 00 0 S 19 AIR FILTER 17 1 12 00 0 BRACKET 04 1 00 35 0 5 AIR FILTER COVE 17 1 07 00 0 41 SHUTTING CLAMA 17 1 09 00 0 SCREW 04 1 00 76 0 HINDER CLAMI 40 17 1 00 03 2 em SILENCER 37 17 1 11 00 1 34 CABLE HOLDER 04 1 00 61 0 4 FRONT DOOR 17 1 06 00 0 PLATE 17 1 00 06 1 ILLUSTRATED 2 9 wring WASHER 13 1 00 07 1 04 1 00 43 0 HEAT EXCHANGER FIXING ROD 17 1 00 02 1 FARTHING LOCKIMSHER 04 1 00 45 0 NUT 04 1 00 42 0 RETURN LABE 27 11 SPRING CLAMP 17 1 00 30 0 CONTROLS PLATE 17 1 00 18 3 53 SCREW TEST POINT 04 1 00 77 0 304100580 33 FLAME LABE 1 JOUTER SHEL 04 1 00 60 0 17 1 03 00 0 32 GAS INLET LAB EI 04 1 00 59 0 3 DEVICE BO 17 1 00 19 0 2 2 22mm GROMMET 04 1 00 49 0 PLASTIC PLUG 04 1 00
15. 30V between terminals SL amp N Is the boiler switched on yes Faulty Switch Neon Replace Is the fan running yes Is the boiler thermostat closed Is there 230V between control box pins 10 amp 2 and between pins 10 and 1 Is the air pressure switch stuck in the NO position Is there 230V between control box pins 6 amp neutral yes no Is the motor relay operating yes mae yes Is there continuity between live supply from relay to blower amp Neutral through motor resistance no Is motor overload tripped no yes Is there wiring continuity no amp in line connector to motor Continued on sheet 2 Apply Power To Boiler Check External Controls Switch On Boiler Boiler return is too hot Allow to cool OR faulty thermostat Replce Check continuity see section 5 3 Faulty pipe connections to Air Press Switch OR Faulty Air Press Switch Replace Control box faulty Relay not secure in socket or relay faulty replace Motor Fan faulty Replace Wait for motor to cool Identify amp correct break Installation amp Servicing Instructions Page 26 WD51 2 1997 Chapter 5 Fault Finding Ce Continued from sheet 1 Y Does ignition sequence start yes Is lockout light on Has the Air Press Switch changed over Are tubes and connections to the Air Press Switch sound Is the air press across the A
16. 4 105 Air Filter 45 114 117 Burner 46 114 118 Burner Manifold Gasket 49 375 527 Ignitor Gasket 50 114 120 Ignitor Sensor Probe 55 104 114 122 Flexible Hose Gasket 63 375 530 Boiler Thermostat 67 375 532 Flue Thermostat 71 375 533 Flow Overheat Thermostat 72 375 534 Flow High Limit Thermostat 90 114 139 Gas Valve Gasket 91 375 536 Gas Multifunctional Control Valve 106 E01 074 Ignition Control Box 109 173 084 Air Pressure Switch 122 E01 075 HT Ignition Cable Installation amp Servicing Instructions Page 50 MM WD 93 0 1997 KESTON CONDENSING BOILERS IMPORTANT KESTON 170 INSTALLATION KEY POINTS Read Installation Manual Carefully Ensure that there is at least 9 feet head of water pressure at the top of the boller DO NOT remove the dust caps from the air and exhaust pipes until ready to connect Ensure that ALL dust particles filings plastic chips etc are removed from the inlet pipe If the installation is a replacement the system must be flushed clean System should be drained hot then refilled then drained again until the water is clean Ensure that there is a proper electrical supply ie 230V fused at 10A Take great care with pipe connections to ensure that no damage is done to the internal pipework Ensure that the 22mm condensate pipe is not exposed to freezing conditions Make sure that the exhaust pipe terminates away from windows or vents and is out of reach Make sure
17. 5 operating efficiency from a Keston condensing boiler Water temperatures in radiant floor heating systems must be kept relatively low generally under 48 C so that surfaces do not become uncomfortably warm to the touch If radiant heating is only one application for a multi zone system which also requires higher delivery water temperatures for other zones i e water heating skirting heaters etc then the radiant floor zone temperature will need to be controlled separately from the boiler If radiant floor heating is the only application of the boiler the boilers maximum operating temperature can be lowered accordingly by introducing a supplementary control thermostat within the control system of the installation Mixing valves are also available which will mix return water from the system with boiler output water to dilute the temperature of water transmitted to the distribution system Mixing valves may create problems with low flow and high temperatures through the boiler unless care is taken to design a system which will provide proper flows and will fully load the boiler Keeping the boiler s temperature high will prevent the boiler from operating at peak efficiencies Systems which maintain boiler temperatures in this way should be avoided Installation amp Servicing Instructions Page 14 WD51 2 1997 Chapter 2 Boiler Connections The Keston 170 Condensing Boiler 2 13 2 14 If only a portion of the boiler s availab
18. 75 0 ELECTRIC MAI 10 SWITCH 30 KESTON LABE 62 FIXING NU 35 WRE RETAINER 17 1 00 29 1 17 1 00 72 0 17 1 00 32 0 04 1 16 00 0 Installation amp Servicing Instructions Page 36 WD51 2 1997 Chapter 5 Fault Finding The Keston 170 Condensing Boiler GR 5 7 5 Exploded Diagrams Parts Reference List Boiler Controls Assembly Fig 5 7 1 GC Number Code Description E01 074 106 Ignition Control Box 170 084 109 Air Pressure Switch 114076 111 Electrical Terminal Block 114077 113 On Off Switch 114078 114 Green Run Lamp 114079 115 Red Lockout Lamp 114 080 116 Pressure Gauge Waterway Condensate amp Flue Assembly Fig 5 7 2 GC Number Code Description 114115 42 Heat Exchanger 114117 45 Burner 114118 46 Burner Head Gasket 114 028 48 Sight Glass 375 527 49 Ignitor Gasket 114 120 50 Spark Ignition Electrode 114 029 53 Pressure Test Nipple 114 032 58 Condensate Trap 375 530 63 Boiler Thermostat 375 532 67 Flue Overheat Thermostat 114 043 69 Combustion Test Plug 375 533 71 Flow Overheat Thermostat 375 534 72 Flow High Limit Thermostat 114 045 73 Water Pressure Switch Air Gas Assembly Fig 5 7 3 GC Number Code Description 114 131 78 Combustion Blower 114146 131 Air Orifice 375 536 91 Gas Valve 114 029 53 Pressure Test Nipple 114073 101 Low Gas Pressure Switch 114 136 87 Gas Injector Casing Assembly Fig 5 7 4 GC Number Code Description 114 095 1 Cabinet 114 108 23 Data Badge 114 099 5 Air Filt
19. Fault FindingThe Keston 170 Condensing Boiler eee 5 7 2 Waterway Condensate amp Flue Assembly WATER WAY CONDENSATE amp FLUE ASSEMBLY K170 17 2 00 00 0 JGNITER GASKET SCREW PRESS TEST Fi 04 2 28 00 0 52 4200251 d 4 Se 1 17 2 00 27 2 3 1 82 SECTION 32 LF lt s COMBUSTIO 48 5e 61455 aimi 69 rEsT PLU 04 2 12 00 1 04 2 00 49 1971 14 7 f U FLUE OVERHEK 6 7 THERMOSTA 04 2 19 00 35 WATER FLO PIPE 17 2 00 22 0 BURNER 45 17 2 04 00 0 SCREW 60 SHEATH GASKET 46 172 00012 17 2 00 57 0 HIGH VOLTAGA WATER OUT 44 LABEL 5 4 MANIFOLD 04 2 00 58 0 172 00 241 HEAT EXCHANGE 4 3 INSULATIO 17 2 03 00 FLOW HIGH LMT 72 THERMOSTA 04 2 22 00 0 D gt HEAT EXCHANGER ZZ X 42197501003 ie Roe WN DAS DO WATER RETURN NS 2 DEA SA WENT 25 RSN Ian n 04 2 21 00 4 GASKET 15 04 2 00 54 0 SCREW q 154541 00 78 0 Ox Y 6 0 DRAN VALVE ex X CONDENSATE TRA d 58554244001 RETUR TV f THERMOSTAT 5 04 2 17 00 q 6 6 8 se HS x WATER PRESSURE 14 ce 13 sich 04 1 00 41 0 04 2 23 00 0 04 2 00 57 0 35 WATER RETUR 50 pire 17 2 00 06 0 CONDENSATE 7 4 SEEGER RING 5 7 TRAP_ HOSE 04 2 00 53 0 04 2 0
20. G Suitable instructions are supplied with the LPG field conversion kits INITIAL FIRING Important Checking the gas pressure to the pre mix burner requires a special procedure outlined below which must be carried out a Purge the gas supply in accordance with BS 6891 b Turn the gas service cock OFF Installation amp Servicing Instructions Page 21 WD51 0 1997 Chapter 4 Commissioning Keston 170 Condensing Boiler ira EE Loosen the screw in the burner pressure test point Figure 5 7 3 item 105 on the gas valve and attach a suitable gauge d Turn on the electrical supply setting any external controls to call for heat ON OFF switch select ON The amber light will illuminate on the ON OFF switch the red lockout light will illuminate the blower and pump will start and after about 15 seconds a spark will attempt to light gas at the burner for approximately 10 seconds With the gas service cock off the boiler will go to lockout red light still illuminated but the blower and pump will continue to run At intervals of approximately 1 minute the boiler will make two further attempts to fire After the final attempt the blower will run for a further 20 seconds before shutting down f Vent the water system Important The Keston heat exchanger consists of a single coil which can trap an air pocket Great care must be taken to ensure that water flow has been established through the heat exch
21. OMSTATS WATER PRESSURE SWITCH IGNITION CONTROL BOX AIR PRESSURE SWITCH COMBUSTION BLOWER GAS CONTROL VALVE GAS LOW PRESSURE SWITCH GAS ORIFICE SPARK IGNITION FLAME DETECTION ELECTRODE BURNER HEAD amp BURNER HEAT EXCHANGER AIR FILTER CONDENSATE TRAP PRESSURE GAUGE SIGHT GLASS HT IGNITION LEAD AIR ORIFICE Installation amp Servicing Instructions Page 41 7 0 7 1 7 2 7 3 7 4 WD51 2 1997 Chapter 7 Replacement Of Parts The Keston 170 Condensing Boilers ee GENERAL The following must always be carried out by a competent qualified person PRECAUTIONS i i Always switch off the mains electricity supply and disconnect the plug at the isolating switch and socket If a switch only is used then remove the fuse Gain access to the appliance Section 7 2 and turn off the gas supply at the appliance service cock ACCESS i ii Remove the front door by removing the three screws to the front of the top panel The front panel may then be removed by tilting forward and lifting vertically to disengage the two locating studs in the base of the front panel Access to the burner head can be gained by removing the access plate in the top panel of the appliance Access to the rear of the control panel and base of the unit can be gained by removing the control panel at the bottom of the boiler Remove the two screws to the control panel then gently pull the control panel free of the boiler c
22. OU JO r lt 50 6 lt gt 263 9 130 gt I lt 405 gt 31 Ue Top View Base View Service Connection Locations All dimensions are in mm Installation amp Servicing Instructions Page 4 WD51 2 1997 Chapter 2 Boiler Connections The Keston 170 Condensing Boiler 2 4 room containing a bath or shower any electrical switch or appliance control utilising mains electricity should be so situated that it cannot be touched by a person using the bath or shower Compartment installation is permitted such compartments must be constructed in accordance with BS 6798 The wall on which the boiler is mounted must be of suitable load bearing capacity and must be non combustible Important It is not recommended to install the boiler on a studded wall or similar it is possible that the vibration from the fan would be amplified and transmitted to other parts of the property Chimneys not used for venting any other appliance may be used Secure air amp flue pipes at NB Refer to Section 2 8 3 Figure 2 3 UR LS Condensate drain The Keston can be located virtually anywhere desired provided that all regulations are complied with Because of the boiler s compact size and venting flexibility the installation is not limited to a boiler room setting Before locating the boiler near a living space consider whether the sounds generated by the boiler will be ob
23. Systems using zone valves must be specifically designed to only fire the boiler when the pump is running and the minimum flow rate can be achieved 2 8 FLUE SYSTEM 2 8 1 2 8 2 Design Individual air supply and flue outlet pipes are used The material used for flue outlet amp or air inlet must be muPVC to BS 5255 an of an internal diameter of 51 mm O56 40 87 80 211 83 Flue Outlet Terminal O56 i Air Intake Ter minal Figure 2 8 1 Terminals Both flue outlet terminal and air inlet terminal are supplied and are illustrated in Figure 2 8 1 above Maximum Lengths The maximum lengths of both air inlet pipe and flue outlet pipe when no bends are used are as detailed below Maximum Air Inlet Length 15 0m Maximum Flue Outlet Length i 15 0 m However each bend used has an equivalent length that must be deducted from the maximum straight length stated above Knuckle bends must not be used A 92 5 sweep elbow is equivalent to 1 0m straight length Example Air inlet uses two one 92 5 sweep elbows Hence maximum length permissible ie a b in figure 2 8 2 15 0m 1 0m 1 0m 13 0m Flue outlet uses one 92 5 sweep elbow Hence maximum length permissible ie c d in figure 2 8 2 15 0m 1 0 m 14 0m Installation amp Servicing Instructions Page 11 WD51 2 1997 Chapter 2 Boiler Connections The Keston 170 Condensing Boiler v gt gt 2 8 3 Slope
24. WD51 2 1997 The Keston 170 Condensing Boiler KESTON Boilers 1 0 000 Btu h 50 kW Model Fan Powered High Efficiency Condensing Gas Boiler Installation And Servicing Instructions Keston 170 GC No 41 930 04 CE No 87AR50 These instructions must be left either with the user or next to the site gas meter KESTON Boilers 34 West Common Road Hayes Bromley Kent BR2 7BX Tel 0181 462 0262 Fax 0181 462 4459 WD51 2 1997 Section 1 G N The Keston 170 Condensing Boiler CONTENTS Description GENERAL INSTRUCTION Description Boiler Schematic Related Documents Performance Data General Data BOILER LOCATION Dimensions amp Minimum Clearances Service Connections Position Electrical Boiler Size Selection Gas Supply Water Systems Flue System Air Supply Compartment Installation Condensate Drainage Radiant Floor Heating Low Water Volume Boiler vs Cast Iron Boiler Determine Radiation Needed Room By Room INSTALLATION OF THE BOILER Wall Mounting Bracket Mounting The Boiler Assembly Practice Installing Flue And Air Pipes Condensate Drainage Water System Gas Supply Electrical Supply Exchanging A Boiler COMMISSIONING OF THE BOILER Initial Flushing Gas Supply Electrical Installation LP Gas Conversion Initial Firing Hot Flushing Checking The Gas Pressure Page i WD51 2 1997 The Keston 170 Condensing Boiler ee 4 8 4 9
25. alves to give independent control of central heating and hot water BOILER SIZE SELECTION The size of the boiler to be used is determined by the total calculated heat loss of the building Match the calculated heat loss with the boilers rated output f a boiler is installed with an output rating greatly exceeding the total capacity of the distribution system the efficiency of the boiler will be reduced GAS SUPPLY A gas meter should be connected to the service pipe by the local gas region or their contractor An existing meter should be checked preferably by the gas region to ensure that the meter is adequate to deal with the rate of gas supply required Installation pipes should be fitted in accordance with BS 6891 Minimum Maximum Natural Gas Pressure Natural gas pressure before the gas valve must be maintained at 20 mbar 8 in WG while the boiler is running Gas pressures above or below this level will lead to problems associated with the gas valve s internal pressure regulator Supply pipes to the boiler must not be sized less than the boiler inlet connection 22 mm Due consideration must be given to the supply pressure to other gas appliances in the premises Reduction in dynamic gas supply pressure will result in intermittent ignition failures Ensure gas supply pipe work is adequately sized for the length of run from the meter to the boiler A gas cock is supplied loose with the boiler This cock should be fitted in the gas line
26. amage the heat exchanger and will invalidate the heat exchanger warranty It is normally advisable to incorporate a boiler by pass in the system especially if thermostatic radiator valves are used The by pass should be fitted with an automatic by pass valve to permit balancing of the by pass flow rate The flow return differential should be 10 C to 15 C The valve should be adjusted to maintain this condition with all thermostatic radiator valves closed Installation amp Servicing Instructions Page 9 WD51 2 1997 Chapter 2 Boiler Connections The Keston 170 Condensing Boiler Ss ee 2 7 5 2 7 6 2 7 7 Air Elimination In the initial charge of water to the boiler system and in all subsequent additions of water to the system some air will be dissolved in the water As the water is heated the air is driven out of the solution and will collect in high spots in the system These air bubbles can interfere with pumping and heat transfer and must be eliminated Installation of air bleed valves at the high spot s in the system will allow for air elimination when filling the system and will allow re venting in a day or so after all air has been driven out of solution Strainers Debris in the heating system can cause noise if it enters the heat exchanger Fitting of a EE at f Y strainer ahead of the Figure 2 7 6 Strainers circulating pump will trap any debris left in the system and will protect
27. anger and thus ensuring no air pockets remain in the heat exchanger and pipe work Firing the boiler while an air pocket exists in the heat exchanger could damage it g Note the reading on the pressure gauge caused by the suction of the blower This should be approximately minus 30 mbar If it is not check the system as follows If the negative pressure exceeds 30 mbar then it suggests that there is a possible restriction in the air inlet pipework If the negative pressure is less than 30 mbar then it suggests that there is a possible restriction in the flue outlet pipework Note the exact reading h Turn the gas service cock to ON i Turn off the electricity supply wait 10 seconds and turn back on The boiler will again go through its ignition sequence but this time the main burner will light provided all air has been purged from the gas supply to the boiler When the burner is lit and the boiler is operating normally the green run lamp the upper lamp adjacent to the flame symbol will also be illuminated indicating successful ignition If it does not and the green lamp is extinguished after 10 seconds air is indicated turn off and repeat the procedure If ignition does not occur the green run lamp the upper lamp adjacent to the flame symbol will be extinguished and at approximately 1 minute intervals the electronic ignition system will make two further attempts to light the burner If the ignition is su
28. asing This is secured by three press studs on either side and a central press stud at the bottom of the control panel REPLACEMENT PROCEDURES i i ii Always replace in the reverse order unless otherwise stated Electrical connections must be remade in accordance with the Wiring Diagram Section 5 5 Test the soundness of any gas carrying or water carrying joint broken during the service procedures ELECTRICAL COMPONENTS 7 4 1 7 4 2 On Off Switch Fig 5 7 1 item 113 i Isolate the appliance Section 7 1 i Gain access Section 7 2 iii Remove the push on connectors from the switch taking note of the correct positions iv Press in the catches and push the switch forwards through the control panel v Reassemble Section 7 3 v Check for correct operation of the switch Boiler Thermostat Fig 5 7 2 item 63 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 iii Remove the push on connectors from the thermostat taking note of the correct positions iv Unscrew the two retaining screws and remove the thermostat Installation amp Servicing Instructions Page 42 WD51 2 1997 Chapter 7 Replacement Of Parts The Keston 170 Condensing Boilers aS v Reassemble Section 7 3 NB When fitting the new thermostat it is an advantage to smear a thin film of heat sink compound between the thermostat and plate This combined with fitting the new therm
29. boiler If the boiler stays put then it is imperative that the front panel and top access plate are replaced and the two plastic pipes capped off whilst drilling Under no circumstances must debris from the wall or cut pipes be allowed to enter the appliance or the plastic pipework Drill the two holes in the wall ceiling preferably using a core drill Diameter of holes i Allowance must be made for socketed lengths if these are to be passed through the holes du unsocketted diameter 56mm ds socketed diameter m 65 mm D ENT D ii For horizontal runs of flue pipe the holes must either be oversized or cut at a 5 slope the latter may be difficult on K L gt long holes Oversizing For every 1m length of run L the x Flue Pipe minimum diameter of the horizontal hole D must be du 10 mm or ds 10 mm respectively assuming the pipe touches the wall at points T otherwise D will have to be increased by clearance from T See Section 3 4 3 Examples Examples a Wall Depth L 750 mm Unsocketted pipe du 56mm Diameter hole D 56 79 1000 x1 0 56 7 5 63 5 mm b Wall depth L 23 ds 65 mm Diameter Hole D 65 2 3x10 65 23 Installation amp Servicing Instructions Page 17 3 5 WD51 2 1997 Chapter Installation The Keston 170 Condensing Boiler DE 88 mm Measure cut and check the air and flue pipes to pass to the exit
30. boiler OR Is there 230V at the gas low faulty switch Replace press switch both terminals Installation amp Servicing Instructions Page 29 WD51 2 1997 Chapter 5 Fault FindingThe Keston 170 Condensing Boiler 5 4 FUNCTIONAL FLOW WIRING DIAGRAM EMC Filter Installation amp Servicing Instructions Page 30 WD51 2 1997 Chapter 5 Fault Finding The Keston 170 Condensing Boiler ee 5 5 ELECTRICAL WIRING DIAGRAM APS AIR PRESSURE SWITCH LEGEND B BLUE L INCOMING LIVE OR ORANGE N INCOMINGNEUTRAL Pk PINK re 2 RAM 2EMC 22 INCOMINGEARTH G GREEN 7 IGNITION CONTROL BR BROWN PUMP 15BR 15 VIOLET GREEN YELLOW lt e o s u upv o 8 7 L L L FLUE OVERHEAT THERMOSTAT e m s 2 1 3 WATER PRESSURE 7 6 4 RELAY SWITCH A m M 90R FLOW HIGH LIMIT FED THERMOSTAT Z BLOWER s i 9 THERMAL FUSE W x 6 Es a 5 FLOW OVERHEAT 4 THERMOSTAT Z F 2 a 5R BOILER EAS THERMOSTAT ON OFF FILTER SWITCH BR Installation amp Servicing Instructions Page 31 WD51 2 1997 Chapter 5 Fault FindingThe Keston 170 Condensing Boiler ee
31. ccessful and the boiler is operating normally the green run lamp the upper lamp adjacent to the flame symbol and the red lockout lamp will be illuminated simultaneously If after three automatic attempts the boiler still fails to ignite the green run lamp the upper lamp adjacent to the flame symbol will be extinguished and the red lockout lamp will remain illuminated If after five manual attempts to allow for purging of any air in the gas line the boiler still fails to ignite indicated by the red lockout lamp refer to Section 5 2 Fault Finding Flow Chart j Check for gas soundness between the gas service cock and connection to the burner manifold Installation amp Servicing Instructions Page 22 WD51 0 1997 Chapter 4 Commissioning Keston 170 Condensing Boiler 4 6 4 7 4 8 4 9 HOT FLUSHING a Allow the system to heat up checking for water soundness b Follow instructions provided with the cleaning agent ie Fernox Supafloc Turn off the boiler and flush the water system while still hot Thoroughly flush the system with clear water Refill the system using a quality water treatment such as Fernox CP3 For sealed systems fill to the required Initial Design Pressure CHECKING THE GAS PRESSURE With the boiler running measure the Fig 4 7 burner pressure at the burner pressure GAS VALVE test nipple The gas setting is factory adjusted to within the required range and should not
32. central heating or pumped central heating with combined indirect sanitary hot water Gravity circuits must not be used Forming part of the boiler is the heat exchanger which is made from a highly corrosion resistant stainless steel formed into tightly wound coil The hot combustion gases from the central down firing burner pass through this coil imparting heat into the system water Head characteristics of the boiler coil must be taken into consideration when calculating the pump size The Keston boiler is not a high water content boiler and does not contain the metal mass or water volume of a cast iron or steel boiler This boiler is of low mass and low water content and therefore responds faster when there is a call for heat This feature requires a higher water pumping rate through the boiler otherwise localised boiling will occur within the boiler Allow a pressure drop through the boiler of 13 75 ft head anda water flow of 13 2 gallons 60 litres per minute The boiler selected must be sized relative to the total calculated heat loss of the building The boiler rated output should not be greater than the total required to make up the calculated heat loss plus the heat required to provide sanitary hot water if the system is not hot water priority design If there are special conditions such as excessive sanitary hot water usage consult the manufacturer BOILER SCHEMATIC Air is drawn into the boiler through a 50mm muPVC pipe The air fl
33. clockwise Reduce CO levels by turning this screw anti clockwise If CO levels do not respond to adjustments the burner is probably running with too much gas pressure If for instance a clockwise adjustment to the brass screw in the gas valve produces a decrease in CO the burner is too fuel rich and not enough oxygen is present for proper and complete combustion HANDING OVER TO THE USER It is important to fully explain the following a Procedure to light and turn off the boiler including isolation of the electrical supply if necessary b The function of the lockout feature must be explained If the red light only is illuminated for more than four minutes this means that the boiler has failed to light Turn off the electrical supply and wait 20 seconds Turn ON again and wait i If lockout recurs immediately then the gas supply should be checked as ON otherwise consult a Service Engineer ii If it is not possible to relight the boiler must be isolated and a Service Engineer called in to rectify the fault Advise that reduction the water pressure reading on the gauge for sealed systems indicates a leak which should be rectified before further use d Advise that the appliance should be serviced by a competent person at least once a year e Advise on frost precautions f Hand over User Instructions Installation amp Servicing Instructions Page 24 WD51 2 1997 Chapter 5 Fault Finding The Keston 170 Co
34. condensate hose to the base of the heat exchanger Installation amp Servicing Instructions Page 46 WD51 2 1997 Chapter 7 Replacement Of Parts The Keston 170 Condensing Boilers ioa 7 7 11 7 12 7 13 7 14 PRESSURE GAUGE Fig 5 7 1 item 116 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 iii Shut off the pressure measurement point at the return drain valve located at the base of the heat exchanger iv Remove the phial from its mounting at the return pipe entry to the base of the heat exchanger v Press in the catches and push the pressure gauge forward through the control panel vi Reassemble Section 7 3 vii Refill the system See Section 4 Commissioning SIGHT GLASS Fig 5 7 2 item 48 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 iii Unscrew the sight glass fitting from the burner head iv Reassemble Section 7 3 HT IGNITION LEAD Fig 5 7 1 item 122 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 iii Remove the lead from the electrode and the ignition control box iv Reassemble Section 7 3 Air Orifice Fig 5 7 3 item 131 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 iii Disconnect the flexible air intake hose from the air inlet manifold Fig 5 7 3 item 83 iv Unscrew the air orifice grub screw Fig 5 7 3 item 84 to release the air orifice v Lift the air orifice from its
35. conds for 2 cubic feet of natural gas and 70 3 seconds for 0 1 cubic metres of natural gas assuming 1038 btu h per cubic foot Adjust the gas valve screw clockwise to increase the input speed up the meter or anticlockwise to decrease the input slow down the meter accordingly COMBUSTION FINE TUNING Although the gas pressure is preset at the factory differing flue arrangements may require fine tuning of the gas pressures to produce the best combustion and ensure long burner life It is advisable to check proper combustion by measuring gas input and the level of carbon dioxide or oxygen in the flue outlet from the boiler Overfiring or underfiring the burner will reduce the longevity of the appliance Installation amp Servicing Instructions Page 23 WD51 0 1997 Chapter 4 Commissioning Keston 170 Condensing Boiler 4 10 Carbon dioxide is a colourless odourless gas produced by all combustion processes When the Keston condensing boiler is operating properly carbon dioxide COz levels will be between 8 2 and 8 9 for natural gas To measure levels in the Keston boiler remove the 1 8 plug from the flue outlet pipe inside the boiler Figure 5 7 2 item 69 Insert the probe of a combustion analysis meter and sample the gases as instructed in the test equipment s instructions If the CO levels need raising increase the gas output by turning the brass screw under the metal cap in the front of the gas valve
36. d is securely fixed Clean or replace burner Does flame stop after 5 10 seconds Is boiler earthed correctly Earth Boiler Are live and neutral supply lines crossed at terminals L amp Correct Wiring N Faulty Control Box Replace Installation amp Servicing Instructions Page 28 WD51 2 1997 Chapter 5 Fault Finding The Keston 170 Condensing Boiler io u a 5 3 CONTINUITY CHECKING To check continuity connect one probe to a neutral and use the other probe to check for 230V Is there 230V at terminal L Check external controls Is there 230V at the ON OFF switch both terminals heplace Boiler is up to temperature Allow to cool OR pump not running OR faulty thermostat Replace Is there 230V at the boiler thermostat both terminals Is there 230V at the flow Thermostat tripped reset OR overheat thermostat both faulty thermostat Replace terminals High cabinet temperature Is nars check all joints for products use link bo erminals 4 leakage Replace thermal fuse Is Mere m i ee High water temperature OR Imittnermosia bo faulty thermostat Replace terminals Check water level header Is there 230V at the water ress switch both terminals tank system pressure OR faulty p 2 i switch Replace Is there 230V at the flue Thermostat tripped reset OR TU URS on faulty thermostat Replace Check gas supply to
37. e electrical supply cable is in the base of the appliance see Section 2 2 Service Connections fig 2 1 2 via a cordgrip bush Feed the cable through this bush and route inside the cabinet to the connection strip located to the front bottom right of the cabinet 1 The electrical supply must be as specified in Chapter 2 Section 2 4 Electrical Supply WARNING THIS APPLIANCE MUST BE EARTHED 2 All external controls and wiring must be suitable for mains voltage Wiring should be in 3 core PVC insulated cable not less than 24 0 2 mm 0 75mm to BS 6500 Table 16 3 The supply connection may be via a 10 amp fused double pole switch serving only the boiler and system controls Refer to Chapter 2 Section 2 4 Electrical Supply 4 Securely tighten the terminal screws and route the cable through the re openable cable clips Ensure all cables are secured and that the cord grip bush is tightened to securely grip the main cable at entry to the cabinet The mains cable must be connected to the terminals as follows A Blue wire Neutral L Brown wire Live Yellow Green Wire Earth Ensure connection is made such that if the cable slips in its anchorage the current carrying conductors become taut before the earthing conductor Installation amp Servicing Instructions Page 19 WD51 2 1997 Chapter Installation The Keston 170 Condensing Boiler EXCHANGING BOILER Before removing an existing boi
38. e in doubt Note Itis equally important to seal the air inlet with solvent cement as the flue outlet pipe joints CONDENSATE DRAINAGE Connect the condensate drainage system to the boiler It is advisable to use a detachable fitting at connection to the boiler to enable easy removal for servicing Fill the condensate trap by pouring water into the boiler flue spigot until water is seen to flow freely from the condensate drainage system Make the final connection of flue pipe to the boiler using the push on coupling supplied Details are provided in Chapter 2 Section 2 11 Condensate Drainage Connection 22 plastic pipe Installation amp Servicing Instructions Page 18 WD51 2 1997 Chapter 3 Installation The Keston 170 Condensing Boiler 3 6 3 7 3 8 WATER SYSTEM Connect the flow and return pipework to the boiler Ensure a detachable coupling is used at connection to the boiler ie compression fitting to enable heat exchanger removal if required Details of system requirements are given in Chapter 2 Section 2 7 Water Systems Connections 35 mm compression X 35 mm compression GAS SUPPLY Connect the gas supply to the appliance Details of gas supply requirements are given in Chapter 2 Section 2 6 Gas Supply Supply of adequate gas pressure with the boiler running is critical to ensure reliable operation of the boiler Connections 0 75 inch BSP male ELECTRICAL SUPPLY The entry point for th
39. ecorded in the Benchmark Log Book You can call CORGI direct on 01256 372300 Page ii WD51 2 1997 s 1 General Instruction The Keston 170 Condensing Boiler 1 1 1 2 1 GENERAL INSTRUCTION DESCRIPTION The Keston Condensing Boiler is unique in its concept and design While the application for which the boiler was designed is the same as those which other boilers are used the Keston boiler has the added advantage of very high efficiency and small diameter plastic flue which can be extended to 15 metres horizontally or vertically The Keston uses a high power combustion blower to deliver a pre mix of gas and air to a downward firing burner in a high efficiency single pass heat exchanger Normally the combustion temperature of the air gas mixture is around 1800 C but the Keston achieves combustion at an amazing 1000 C thereby reducing the NO emissions The flue system is room sealed and fan powered The ignition is direct spark and fully automatic The boiler housing is not waterproof The boiler should be installed in a position where it will always be dry A small air intake point is incorporated within the appliance cabinet to ensure that the interior of the cabinet is maintained under a slight negative pressure This is a safety feature to ensure no products may leak out of the cabinet into the installation space The boiler is suitable for connection to open vented or preferably sealed systems The system must be pumped
40. er Cover 114105 19 Air Filter 114 096 2 Cabinet Top Cover 114 100 6 Burner Access Cover Plate 114 109 29 Illustrated Wiring Diagram 114 098 4 Front Door Installation amp Servicing Instructions Page 37 WD51 2 1997 Chapter 6 Servicing The Keston 170 Condensing Boiler oVwW 6 ROUTINE ANNUAL SERVICING To ensure the continued safe and efficient operation of the boiler it is necessary to carry out routine servicing at regular intervals The frequency of the servicing will depend upon the particular operating conditions but it is recommended that an annual service should be carried out by a qualified engineer The appliance has an integral air filter mounted at the top right hand side of the boiler to which the air intake pipe is connected This filter should be examined every time the boiler is serviced It may need more frequent inspection according to the condition of the atmosphere in which the air intake terminates Note The air filter can be easily blocked if the boiler is running on or near a building site having an excess of airborne dust It is essential with a premix gas burner that the air is clean and free of dust It is the law that any service work must be carried out by competent qualified persons 6 1 Pre Service Checks It is recommended that an inspection should be carried out prior to shutting down the unit for servicing Remove the front cover by removing the screws retaining the t
41. exchanger warranty The air intake terminal must face upwards to prevent entry of rain into the air intake pipework The flue outlet terminal is designed to face outwards but can if desired be Installation amp Servicing Instructions Page 12 WD51 2 1997 Chapter 2 Boiler Connections adapted to face in any direction BUT must not be directed in the region of the air inlet The Keston 170 Condensing Boiler Dimensions mm Flue Air Terminal Inlet A Below openable window air brick etc 300 50 B Below gutters soil pipes drain pipes 75 75 C Below eaves 300 50 D Below balconies or car port roof 200 50 E From vertical drain or soil pipes 75 50 F From internal or external corner 600 50 G Above ground or balcony or roof 300 100 H From surface facing a terminal 600 100 From terminal facing a terminal 1 200 1 200 J From opening in a car port 1 200 100 K Vertically from terminal on same wall 1 500 1 500 L Horizontally from terminal on same wall 300 300 Table 2 8 4 Minimum Flue Terminations amp Air Inlet Dimensions The two terminals are subject to the requirements of BS 5440 Pt 1 for clearances from features of the building although some can be decreased to the values indicated If either the air inlet or the flue outlet terminate at a height of less than 2m 6ft above ground level the termination must be protected by a suitable guard The K4 terminal guard manufactured by Towe
42. fixed behind the lower mounting screw 7 4 8 Combustion Blower Fig 5 7 3 item 78 NB vii This unit is heavy and must therefore be handled carefully when replacing Isolate the appliance Section 7 1 Gain access Section 7 2 Disconnect the wires connecting the blower to the relay relay terminals number 6 and 3 Remove the allen screws fixing the air intake pipe flange and the gas air mixture pipe flange to the blower Unscrew the three bolts fixing anti vibration mounts to the combustion blower through the base of the cabinet Reassemble Section 7 3 NB When reassembling inspect any gaskets for damage and replace if necessary Reset the gas rate See Section 4 Commissioning 7 4 9 Gas Control Valve Fig 5 7 3 item 91 xii xiii Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the cover concealing the electrical connections on the front of the gas valve Remove the push on connectors exposed taking note of the correct positions Remove the push on connectors to the gas low pressure switch taking note of the correct positions Remove the earth connection to the side of the gas valve Remove the plastic air tube to the base of the gas valve Remove the four allen screws securing the gas inlet flanged connections to the gas control valve Undo the four bolts fixing the base of the gas control valve to the gas outlet block Remove the gas valve Unscrew the gas low pressure swi
43. from the wall s or ceiling Always thoroughly deburr all pipes and most important remove shavings from within the pipe d Assemble using adhesive the pipework from the boiler connections to the exit from the first wall ceiling remount the boiler if removed When pushing pipe through walls ensure grit and dust is not allowed to enter the pipe Ensure pipes are fully engaged into sockets Connect the condensate drainage system and fill the condensate trap by pouring water down the boiler flue spigot See Section 3 5 Condensate Drainage Make the final connection of flue and air pipe to the boiler using push on or plastic compression couplings Ensure that the connectors are set vertically otherwise leakage of condensate may occur which will corrode the casing Do not use adhesive on the push on end of the connecting couplings Fully Engaged Adhesive Using the same methods drill any further holes always covering existing F A pipework cut and assemble the pipework f From outside complete the two terminations See Section 2 8 Flue System and make good all holes g Support any pipes whose route could be displaced either of its own accord or by accident Any horizontal run over 1m or vertical runs of any length must always be supported Brackets should be placed at intervals of approximately 1m h Check all connections for security and re seal any joints using sovent cement where soundness may b
44. ght iv The pressure difference should be below 14 mbar If not clean the burner v Turn off the electrical supply to the boiler vi Remove the pressure point screw from point C and transfer the tube from point A to C replacing the screw on point A Installation amp Servicing Instructions Page 38 WD51 2 1997 Chapter 6 Servicing The Keston 170 Condensing Boilers Fl Pressure Test Pressure Test Point A Point B bb D ii Flue Over heat Exchanger 4 e Ed Ther mostat Shell O Combustion Test Point amp Burner Heat From Above Pressure Test Point Fig 6 11 Pressure Test Point Locations vii Turn on the electrical supply to the boiler gas still off wait for the fan to reach full speed viii The pressure difference should be below 17 mbar If not clean heat exchanger ix Disconnect the gauge from point B Refit the screw x Read pressure of point C xi The maximum pressure should be 3 5 mbar If the pressure is greater than this check the flue for blockage xii Turn off the electrical supply to the boiler xiii Remove the pressure gauge tube and refit the screw xiv Open the gas service cock 6 2 Recommended Routine Service a Inspect the air filter located at the top right hand side of the boiler Release the toggle catch on the filter tray and remove the filter If the filter looks dirty remove the dirt with a vacuum cleaner or by other means If
45. ghtly acidic about the same acidity as vinegar and should be piped in a plastic pipe It is not harmful to the waste disposal system and may be disposed of as normal waste water The flue gases are piped in a 50mm muPVC pipe to the outside The temperature of the flue gases are usually around 10 C above the temperature of the return water The flue pipe should be terminated outside the building from where they cannot re enter the building or any other adjacent building The heating level may be controlled by room thermostats hot water cylinder thermostats programmer time clocks and energy management systems 1 3 RELATED DOCUMENTS The Keston Condensing Boiler must be installed in accordance with the current issue of the Gas Safety Installation and Use Regulations current IEE Wiring Regulations Building Regulations Building Standards Scotland Consolidation and the Bye Laws of the local Water Undertaking In addition due account must be taken to the following Codes Of Practice BS 6891 Gas Supplies BS 6798 Installation Central Heating Boilers BS 5449 Installation Pumped Central Heating BS 5546 Installation Domestic Hot Water BS 5440 1 Flues Installation amp Servicing Instructions Page 2 WD51 2 1997 s 1 General Instruction The Keston 170 Condensing Boiler BS 5440 2 7 Air Supply BS 5482 1 Domestic Propane amp Butane Burning Installations BS 7074 1 Expansion Vessels BS 7593 Treatment of Wa
46. iance Gain access Section 7 2 Drain the system to below the level of the appliance using the drain off tap at the base of the heat exchanger Remove the push on connectors from the water pressure switch taking note of the correct positions Unscrew the pressure switch Reassemble Section 7 3 NB Use a little jointing compound or PTFE tape on the thread Refill the system See Section 4 Commissioning 7 4 6 Ignition Control Box Fig 5 7 1 item 106 i i ii iv v Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the HT ignition lead Pull off the multi pin connector away from the box Unscrew the two screws securing the control box to the casing and remove the box Installation amp Servicing Instructions Page 43 WD51 2 1997 Chapter 7 Replacement Of Parts The Keston 170 Condensing Boilers 1 _ _ _ Reassemble Section 7 3 7 4 7 Air Pressure Switch Fig 5 7 1 item 109 Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the push on connectors from the air pressure switch taking note of the correct positions Disconnect the union to one plastic tube connection and pull off the second plastic tube from the air pressure switch Unscrew the two screws mounting the air pressure switch body to the boiler casing Reassemble Section 7 3 NB Ensure the yellow green earth connection tag is securely
47. ignition electrode flange located on the burner head and withdraw the spark ignition electrode Reassemble Section 7 3 NB When reassembling inspect the gasket for damage and replace if necessary With the new spark ignition electrode in place it is essential to ensure the gap between the tip of the electrode and the burner surface is 4 mm Distance above or below 4 mm will affect the ignition performance If necessary gently bend the electrode taking care not to damage the ceramic insulator 7 7 BURNER HEAD amp BURNER Fig 5 7 2 items 47 amp 45 i ii vii vi vii Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the pull off HT lead to the spark ignition flame detection electrode head Remove the four screws retaining the access panel Fig 5 7 4 item 1 and remove the access panel from the top of the cabinet Remove the two allen screws fixing the flange gas air mixture pipe connection to the burner head Remove the five allen screws fixing the burner head to the top of the heat exchanger Withdraw the burner amp burner head from the top of the heat exchanger through the access panel opening in the top of the cabinet Unscrew the burner from the burner head taking care not to damage the burner mesh Reassemble Section 7 3 NB When reassembling inspect any gaskets for damage and replace if necessary Set the spark gas as detailed in Section 7 6 Reset the gas rate see Section 4 C
48. ir Press Switch more than 4 in water Is the air filter dirty or the air inlet exhaust or condensate pipe blocked Is the Burner blocked Fan faulty change Is the gas flow rate to the boiler correct for the gas type in use ie LPG or Nat Gas yes Is gas supply pressure at gas valve correct 15 gas burner pressure per specification Section 4 7 Is gas valve opening Continued on sheet 3 The Keston 170 Condensing Boiler Switch off amp if problem persists replace control box Blocked air filter replace OR Faulty control box replace Correct tube connection Faulty pressure switch replace Replace air filter OR clear blockage Clear blockage Check gas supply or turn on gas cock Replace gas orifice Faulty gas valve replace From sheet 3 Installation amp Servicing Instructions Page 27 WD51 2 1997 Chapter 5 Fault FindingThe Keston 170 Condensing Boiler ee Continued from Sheet 2 Continued on sheet 2 Is there 230V at valve Faulty Gas Valve Replace Is there 230V at Gas Low Faulty Gas Low Pressure Press Switch Switch Replace Faulty Control Box Replace Is there a spark present yes Is the HT voltage present at top of ignition electrode Faulty Conrtrol Box Replace Is the spark gap 4 mm Replace Adjust Spark Plug yes Electrode Faulty Replace Does the burner ignite es y no Recheck gas output pressure Check HT lea
49. itable In any event reference must be made to BS 7593 Treatment Of Water In Hot Water Central Heating Systems a Disconnect the boiler from the system at the flow and return connections and temporarily link the flow and return pipes on the system b Flush the entire system until clean water is discharged free from dirt flux solder etc The use of a flushing chemical is recommended e g Fernox Supafloc Sludge and scale must be removed from an existing system Boiler failure due to system debris or sludge shall invalidate the guarantee Connect the system to the boiler and fill in accordance with Section 2 7 Water Systems At this stage for sealed systems fill to a pressure of about 2 7 bar d Check the complete system for water soundness If leaks need to be rectified using flux and solder the system must be flushed cold again before proceeding e Reduce the pressure to the Initial System Design Pressure for sealed systems if applicable Vent the system GAS SUPPLY The complete gas installation up to the boiler service cock must be checked for soundness BS 6891 ELECTRICAL INSTALLATION Carry out preliminary electrical safety checks i e Earth continuity Polarity Resistance to Earth Short Circuit using a suitable test meter LP GAS CONVERSION All Keston condensing boilers are built and shipped as natural gas fired units Field conversion kits are available to convert Keston condensing boilers to use LP
50. jectionable ELECTRICAL 2 4 4 Electrical Connections The boiler must be connected to a 230V 50Hz supply fused at 10A All external controls and wiring must be suitable for mains voltage Wiring external to the boiler must be in accordance with current E E wiring regulations and local regulations The method of connection to the mains electricity supply must facilitate complete electrical isolation of the boiler preferably by the use of a fused Installation amp Servicing Instructions Page 5 2 5 2 6 2 7 WD51 2 1997 Chapter 2 Boiler Connections The Keston 170 Condensing Boiler unswitched three plug and a shuttered socket outlet both complying with the requirements of BS 1363 The appliance must be connected to the supply via a fused double pole switch having at least 3mm 1 8 inch contact separation in both poles serving only the boiler and the system The connection point to the mains supply should be readily accessible and adjacent to the boiler except for rooms containing a bath or a shower Refer to section 2 3 Position 2 4 22 External Wiring amp Controls 1 The boiler is deisgned so that all control wiring is external to the boiler Hence any programmers or room thermostats etc must act by switching the 230V supply to the boiler 2 System designs which allow the boiler to fire when there is no pumped circulation must NOT be used 3 A programmer may be used with zone v
51. l bracket b Move the boiler sideways to centralise the boiler on the bracket Screw the lower fixing screw 3 3 ASSEMBLY PRACTICE Remove all plastic debris and burrs when installing air intake piping Plastic filings caused by cutting muPVC pipe must not be allowed to be drawn into the filter or combustion air blower Prevent dust entering the air intake when cutting on building sites Blower failure which is determined to be caused by plastic filings or other debris will not be covered by guarantee Combustion air filters are fitted to the Keston condensing boilers as standard This filter must be examined at least once every year and more often in particularly dusty and dirty areas N Installation amp Servicing Instructions Page 16 WD51 2 1997 Chapter 3 Installation E LLL 3 4 The Keston 170 Condensing Boiler The combustion air filter will prevent plugging of the burner caused by dirt being trapped in the burners outer mesh The filter element supplied with the boiler is obtainable from Keston Boilers or its distributors INSTALLING FLUE AND AIR PIPES Remember the flue pipe must slope downwards back towards the boiler and this is best achieved using 92 5 bends a 3 4 1 3 4 2 3 4 3 From the two connections on the boiler mark the positions of the two holes for the flue and air pipes on the wall s or ceiling To allow access to drill the holes it may be necessary to temporarily remove the
52. le output is to be used for radiant floor heating a thermal storage tank will improve the boiler s operation and give adequate control of temperature for the distribution system By heating water to be distributed to the radiant floor zone to the proper temperature in an indirect fired water heater full load conditions will be available to the boiler because the heat exchanger in the tank can be sized to match the boiler s output The tank s thermostat can be set at the optimum operating temperature needed by the distribution system and short cycling of the boiler will be prevented An insulated thermal storage tank without the heat exchanger may also be used LOW WATER VOLUME BOILER VS CAST IRON BOILER Because of their high water content and mass of metal cast iron and steel boilers are less responsive but somewhat more forgiving of design errors Short cycling of the burner on the temperature limit control is less pronounced though no less detrimental to operation because the boiler itself will absorb and radiate a significant amount of heat Low water volume boilers respond more quickly to a call for heat can be made more compact and lightweight but must have adequate heat delivery systems to avoid short cycling of the burner on the temperature limit control The heat delivery system s output must be equal to or greater than the boiler s output to fully load the boiler or short cycling will occur Likewise pumping rates of water through low
53. ler Connections The Keston 170 Condensing Boiler Boiler Drain Cock Keston Make up vessel Max capacity of Air Vent 3 It Spt X Non Return Hose Valve Union L bib tap E Auto Air Vent x L S Strainer lt lt lt RETURN HEATING CIRCUIT Hosepipe disconnected gt LOW after filing Safety 8 Valve LJ Sd Expansion Double Check Hose Vessel BS 0102 Valve Stop Tap Connector Test Cock 2 7 3 2 7 4 Figure 2 7 2 Sealed System Diagram All components of the system including the heat exchanger of the indirect cylinder must be suitable for a working pressure of 3 bar and a temperature of 110 C Care should be taken in making all connections that the risk of leakage is minimised Hot Water System if applicable The hot water storage vessel must be of the indirect type certain direct cylinders can be used provided they are suitably adapted by fitting an immersion calorifier DIRECT CYLINDERS MUST NOT BE USED Further guidance is provided in BS 1394 It is advisable to fit a lockshield valve on the cylinder return to enable balancing of the flow rate through the cylinder Boiler By pass Piping Boiler water flows are critical to the operation of the boiler If flow cannot be maintained through the system piping to meet the minimums required by the boiler see paragraph 2 7 g Insufficient water flows through the boiler will cause the boiler to kettle or even produce steam which can d
54. ler add Fernox Supafloc or equivalent cleaning agent in accordance with the manufacturers instructions Open all radiator valves and fire the boiler When the system is fully heated shut off the gas supply and drain down the central heating system Important The Keston condensing boiler contains components which could be damaged or blocked by grease dirt or solder etc It is essential that sludge or scale is removed from an existing system As safety precaution it is advisable to fit an in line strainer before the boiler The guarantee provided with the Keston 170 does not cover damage caused by system debris or sludge Connect the new boiler as instructed in this manual and fit in accordance with Sections 3 1 to 3 8 For sealed systems fill to a pressure of about 2 7 bar Check the complete system for water soundness If leaks need to be rectified using flux or solder the system must be flushed cold again before proceeding Reduce the pressure to the Initial System Design Pressure for sealed systems if applicable Vent the system Gas Supply The complete gas installation up to the boiler service cock must be checked for soundness BS 6891 Electrical Installation Carry out preliminary electrical safety checks i e Earth continuity Polarity Resistance to Earth Short Circuit using a suitable test meter Initial Firing The gas pressure setting is factory adjusted to within the required range and GAS VALVE should not
55. ly causes loss of the flame the control box will pause for approximately 10 seconds and then attempt to re ignite the unit If this attempt fails i e due to continued lack of gas supply the boiler will make two further attempts to ignite at intervals of approximately 1 minute and will then go to a lockout state red lamp illuminated only Once the gas supply has been resumed the boiler can be reset by turning the boiler off and then on again on the boiler control panel 7 The boiler can also be shut down by any of the flow limit flow overheat and the flue overheat thermostats gas low pressure switch and by the low water pressure switch In such an event the green run lamp the upper lamp adjacent to the flame symbol will be extinguished and only the red lockout lamp will be illuminated Any failure of the boiler to sequence in the above manner should be investigated using the following trouble shooting flow diagram Before attempting any electrical fault finding always carry out preliminary electrical system checks On completion of any service fault finding task which has required the breaking and remaking of electrical connections the checks earth continuity polarity short circuit resistance to earth must be repeated Installation amp Servicing Instructions Page 25 WD51 2 1997 Chapter 5 Fault FindingThe Keston 170 Condensing Boiler 5 2 FAULT FINDING FLOW CHART Is amber switch light on yes Is there 2
56. nd the heat exchanger Remove the allen screw securing the top of the heat exchanger to its mounting bracket Remove the heat exchanger with pipework attached Remove the flow return and flue pipework from the heat exchanger Replacement heat exchangers are supplied with return pipework attached Reassemble Section 7 3 Recommission Section 4 Commissioning 7 9 AIR FILTER Fig 5 7 4 item 19 Isolate the appliance Section 7 1 Gain access Section 7 2 Drop the lower section of the air filter housing by releasing the toggle clip Open the lower section as far as possible and pull out the combined paper filter element with rubber seal Reassemble Section 7 3 NB When fitting the new air filter take care to ensure that the new filter is placed to cover completely the air intake into the boiler cabinet 7 10 CONDENSATE TRAP Fig 5 7 2 item 58 i ii iii iv v vi vii viii Isolate the appliance Section 7 1 Gain access Section 7 2 Disconnect the condensate line from the base of the heat exchanger Disconnect the condensate line from the base of the flue assembly Disconnect the condense lines from the projection of the condensate trap from the base of the cabinet Withdraw the condensate trap Mop up any spilled condensate Reassemble Section 7 3 NB When re fitting the condensate trap pour water onto the condensate hose from the base of the heat exchanger until nearly full Then reconnect the
57. ndensing Boiler Y 5 FAULT FINDING 5 1 ELECTRICAL CONTROL SEQUENCE When the external controls are calling for heat power will be fed to the boiler connection strip at terminals L Live and N Neutral If the ON OFF switch is also in the ON position the boiler ON lamp amber will be illuminated Provided all temperature thermostats and pressure switches are closed power will be fed to pins 1 amp 2 on the control box initiating the following sequence 1 The boiler lockout lamp red will be illuminated 2 The fan will start 3 When the fan reaches running speed the Air Pressure switch normally open will close which will start the ignition sequence 4 After a pre purge period of about 15 seconds the gas valve will open to allow gas to mix with the air at the suction side of the fan and the ignition spark will occur at the main burner 5 When the burner ignites the flame is detected by the control box through the combined flame sensor ignitor and the ignition spark is stopped Both the lockout lamp red and the boiler run lamp green the upper lamp adjacent to the flame symbol will be illuminated The boiler is now in its normal run condition 6 The burner will continue to operate until the gas valve interrupts the gas supply The gas valve will be closed by the control box if power is interrupted to the boiler by any external control or the boiler thermostat If an interruption to the gas supp
58. normally need re adjustment If the reading is incorrect then such factors as soundness of the air and flue pipe joints pressure sensible joints and the gas inlet pressure 20 mbar required If all joints are sound and the gas inlet pressure is satisfactory set Burner pressure the gas pressure to the required Adjustment pressure Full details of this procedure are given in Section Burner pressure 4 7 This will ensure that test nipple gt combustion is good enough to allow combustion fine tuning to take place check Combustion Fine Tuning It is advisable on all installations that the combustion quality is checked by measuring the carbon dioxide CO or oxygen level This procedure is detailed in Section 4 9 Combustion Fine Tuning Badly tuned combustion will lead to reduce the life of the boiler and invalidate the warranty Installation amp Servicing Instructions Page 20 WD51 0 1997 Chapter 4 Commissioning The Keston 170 Condensing Boiler 4 COMMISSIONING OF THE BOILER Important This condensing boiler contains components which could be damaged or blocked by grease dirt solder etc from the water system The following commissioning procedures must be followed precisely 4 1 4 2 4 3 4 4 4 5 INITIAL FLUSHING All waterways within the Keston are either copper or high alloy stainless steel As a result standard water treatment chemicals for conventional central heating boilers are su
59. ommissioning Installation amp Servicing Instructions Page 45 WD51 2 1997 Chapter 7 Replacement Of Parts The Keston 170 Condensing Boilers c o 77 7 8 HEAT EXCHANGER Fig 5 7 2 item 42 i i ii xvi xvii xviii xix xx xxi Isolate the appliance Section 7 1 Gain access Section 7 2 Shut of the water supply to the appliance Remove the burner head Section 7 7 Drain the system to below the level of the appliance using the drain off tap at the base of the heat exchanger Remove the front control panel Section 7 2 iii Remove the boiler thermostat Section 7 4 2 Remove the push on connectors to the water pressure switch flow overheat thermostat flow high limit thermostat and flue protection thermostat taking note of the correct positions Remove the condensate trap Section 7 10 Remove the pressure gauge phial located next to the drain off tap Remove the air filter Section 7 9 Remove the two springs connecting the bottom tray of the air filter with the cabinet top cover Disconnect the flow and return connections to the boiler Remove the push on flue and air connections to the flue and air pipes exiting the top of the boiler Remove the four screws fixing the cabinet top cover to the cabinet body and remove the top cover Remove the nut fixing the strap retaining the base of the heat exchanger and pull out the strap by unhooking it from its fixing behi
60. op of the door and lifting the cover from the base Front cover located by two pegs The following items should be observed Smooth starting and running of the blower Smooth lighting of the burner Check for leakage of gas gas air or combustion products Check for condensate leaks Check the colour and appearance of the flame A sky blue flame slightly off the burner gauze is normal The burner itself should appear dark Any glow on the burner indicates gauze blockage requiring cleaning an incorrect gas flow or an air intake blockage f Check that the temperature differential between the flow and return pipes is less than 15 C The temperature difference should be between 10 C and 15 C Check for water soundness Inspect the flue vent and air intake pipework Joints must be sound and all pipework well bracketed i Check that there is a steady fall back to the boiler from the flue pipe to allow condensate to run back into the boiler See Section 2 8 3 Slope j With the boiler operating at a low return temperature i e less than 50 C check that the condensate flows freely from the condensate line ooo o e 6 1 1 Burner amp Heat Exchanger Blockage Checks i Turn off the boiler amp shut off the gas supply to the boiler ii Remove the pressure point screws from points A amp B Attach a differential gauge iii Turn on the boiler and wait for the fan to reach full speed Obviously the burner will not li
61. ostat tightly to the plate ensures a good contact 7 4 3 Neons Fig 5 7 1 items 114 amp 115 i ii iii iv v vi vii Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the push on connectors from the neon taking note of the correct positions Press in the catches and push the neon forward through the control panel Pull the centre core of the neon from its housing to expose the bayonet fitting bulb Reassemble Section 7 3 Check for correct operation of the neons 7 4 4 Flow Overheat Fig 5 7 2 item 71 Flow High Limit Fig 5 7 2 item 72 amp Flue Protection Thermostats Fig 5 7 2 item 67 Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the push on connectors from the thermostat taking note of the correct positions Unscrew the two retaining screws and remove the thermostat Flue protection thermostat only The thermostat seal is maintained via a small O ring between thermostat and flue pipe If this is damaged on removal it must be replaced Reassemble Section 7 3 NB When fitting the new thermostat it is an advantage to smear a thin film of heat sink compound between the thermostat and plate This combined with fitting the new thermostat tightly to the plate ensures a good contact 7 4 5 Water Pressure Switch Fig 5 7 2 item 73 i ii iii iv v vi vii viii Isolate the appliance Section 7 1 Shut off the water supply to the appl
62. ow is proved by a differential pressure across the air control orifice Gas is mixed with combustion air at the inlet to the fan The gas flow is regulated by an orifice located in the housing downstream of the gas valve The gas and air are thoroughly mixed in the blower and fed into the burner located at the top end of the heat exchanger module The gas and air mixture is ignited by a direct spark ignition control system and burns with a blue flame just off the surface of the burner As the hot products of combustion pass downwards they are cooled by exchanging heat with the circulating water which enters the heat exchanger coil at the bottom of the heat exchanger Fig 1 2 Boiler Schematic Installation amp Servicing Instructions Page 1 WD51 2 1997 s 1 General Instruction The Keston 170 Condensing Boiler When the return water temperature is below 54 C part of the water vapour in the combustion products will condense inside the heat exchanger thus increasing the boiler efficiency by releasing the latent heat of condensation This condensate falls to the bottom of the heat exchanger where it is separated from the flue gases and exits from the boiler through the condensate drain Any condensate formed in the flue runs back down the flueway and is drained at the base of the flue connection to the heat exchanger or drain points within the flue The condensate is very sli
63. r Flue Components Ltd is suitable for this purpose and can be obtained from Keston Boilers The Keston condensing boiler as with any condensing boiler will generate a condensate plume from the flue terminal in all weather conditions Consideration must therefore be given to the effect of this plume when selecting a location for the flue terminal It is advisable for horizontal flue terminals to place a 45 elbow at the end of the flue to direct the condensate plume up and away from the property 2 8 5 Clearances From Wall Flue outlet and air inlet terminations must be at least 60 mm and 95 mm respectively from the wall face 2 8 6 Distance Between Flue Outlet amp Air Inlet There is no maximum the terminations can be on opposite sides of the dwelling if desired A minimum clearance of at least 500 mm must be left between the terminations 2 8 7 General Installations All parts of the system must be constructed in accordance with BS 5440 Part 1 except where specifically mentioned in these instructions All pipework must be adequately supported Installation amp Servicing Instructions Page 13 WD51 2 1997 Chapter 2 Boiler Connections The Keston 170 Condensing Boiler 2 9 2 10 2 11 2 12 All joints other than or plastic compression connectors must be made and sealed with solvent cement suitable for muPVC pipes and conforming to BS 6209 1982 External wall faces and any internal faces
64. s Page 15 WD51 2 1997 Chapter Installation The Keston 170 Condensing Boiler j 3 INSTALLATION OF THE BOILER Read Chapter 2 Boiler Location and decide upon the position of the boiler Installation of the boiler is straightforward but consideration must be given to access to allow flue and air pipes to be pushed through walls and ceilings The order in which the components are installed will depend upon particular site conditions but in general it will be easiest and most accurate to install the boiler and then build up the flue outlet and air inlet pipes to the terminal this is the sequence described 3 1 WALL MOUNTING BRACKET a Place the bracket on the wall horizontally with the pre drilled JM holes at the bottom All dimensions in mm b Drill through the centre hole of v the bracket plug the hole and fix 93 in position Using a spirit level make sure the bracket is completely level and mark the position of the other screw holes d Remove the bracket and drill the holes in the positions marked Plug these holes Screw the bracket to the wall using screws of an appropriate 280 size for the wall type No 12 x 2 inch wood screws normally 250 suffice f Mark the bottom fixing hole and drill for a No 8 x 1 inch wood screw Insert plug Figure 3 1Wall Mounting Fixing Locations 3 2 MOUNTING THE BOILER a Lift and locate the upper rear lip on the boiler to the boiler wal
65. seat in the air inlet manifold vi Reassemble Section 7 3 NB When replacing the air orifice ensure that the new orifice is seated with the chamfer facing upwards Installation amp Servicing Instructions Page 47 WD51 2 1997 Chapter 8 Spare Parts Listings The Keston 170 Condensing Boiler 8 SHORT SPARE PARTS LIST Item GC No Part Denomination Item GC No Part Denomination 19 114 105Air Filter 45 114 117Burner 46 114 118Burner Manifold Gasket 49 375 527lanitor Gasket 50 63 375 530Boiler Thermostat 67 375 532Flue Thermostat 71 375 533Flow Overheat Thermostat 72 375 534Flow High Limit Stat Installation amp Servicing Instructions Page 48 WD51 2 1997 Chapter 8 Spare Parts Listings The Keston 170 Condensing Boiler Item GCNo Part Denomination Item GCNo Part Denomination 90 375 535Gas Valve Outlet Gasket 104 114 122Flexible Hose Gasket 91 375 536Gas Valve 106 E01 074 Ignition Control Box 109 170 084Air Pressure Switch 122 E01075 HT Ignition Cable Installation amp Servicing Instructions Page 49 WD51 2 1997 Chapter 8 Spare Parts Listings The Keston 170 Condensing Boiler 7 7 0 SHORT SPARE PARTS LIST FOR THE KESTON CONDENSING BOILER RANGE Item GC No Part Denomination 19 11
66. tch at its connection to the gas control valve body Reassemble Section 7 3 Reset the gas rate See Section 4 Commissioning 7 4 10 Gas Low Pressure Switch Fig 5 7 3 item 101 i Isolate the appliance Section 7 1 Installation amp Servicing Instructions Page 44 WD51 2 1997 Chapter 7 Replacement Of Parts The Keston 170 Condensing Boilers ee ii Gain access Section 7 2 iii Remove the push on connectors to the gas low pressure switch taking note of the correct positions iv Unscrew the gas low pressure switch from the brass holder v Reassemble Section 7 3 75 GAS ORIFICE Fig 5 7 3 item 87 i ii iii iv v vi vii viii Isolate the appliance Section 7 1 Gain access Section 7 2 Unscrew and remove the brass plug from the gas outlet block Remove the rubber seal from the injector housing Insert a flat blade screwdriver into the exposed hole and unscrew the gas injector Check the injector is the correct size for the boiler size and fuel type Reassemble Section 7 3 NB Ensure that the injector is screwed fully home Reset the gas pressure See Section 4 Commissioning 7 6 SPARK IGNITION FLAME DETECTION ELECTRODE Fig 5 7 2 item 50 i ii iii iv v vi Isolate the appliance Section 7 1 Gain access Section 7 2 Remove the pull off HT lead to the spark ignition electrode Remove the burner head Section 7 7 steps iv to vi Undo the screws to the spark
67. ter in Hot Water Central Heating Systems BS 7671 Requirments for Electrical Installations IEE Wiring Regulations 16th Edition For Timber Framed Buildings British Gas Publications DM2 Also British Gas Publications Guidance Notes For The Installation Of Domestic Gas Condensing Boilers and Specification For Domestic Wet Central Heating Systems 1 4 PERFORMANCE DATA Boiler Input gross kW 55 0 Max Operating Flow Temp C 80 00 187 600 Max Head Open Systems m 30 50 Boiler Output To Water kW 49 8 Ft 100 0 80 C Flow 60 C Return Btu h 170 000 Max Press Sealed Sys Bar 2 70 Boiler Output To Water kW 52 4 60 C Flow 40 C Return Btu h 179 000 Min Head Open Systems m 2 5 Ft 8 0 Boiler Output To Water kW 54 5 50 C Flow 30 C Return Btu h 186 000 Inlet Gas Pressure mbar 20 0 inwg 8 0 Burner Setting Pressure mbar 10 0 Hot inwg 3 94 Gas Orifice Size mm 4 5 Gas Comsumption After 5 1 42 Air Orifice Size mm 23 0 10 mins Running Ft hnr 180 73 CV of Gas 38 7 MJ m Recommended Temperature C 10 to 15 1038 Btu Ft Differential 1 5 GENERAL DATA Main Burner Keston Premix Flow Connection 35mm Copper Gas Control White Rogers 36E Series Return Connection 35mm Copper Combustion Fan Keston Power Supply 230V 50Hz Type LPB 103 220 240 0 6 kW 2900 RPM Pwr Consumption 670 W Direct Spark RAM Electronicslgnition Ext Fuse Rating 10 Amps Ignition Full Sequence Control Weight Full 68 kg 150 Ibs
68. to the boiler as close to the boiler as possible so that it is easily identified as the cock to isolate the boiler WATER SYSTEMS All piping must be installed in accordance with all applicable local and Water Supply Bylaws for forced hot water heating systems Consideration must be given to pipe capabilities and pressure drop through the piping Installation amp Servicing Instructions Page 6 WD51 2 1997 Chapter 2 Boiler Connections The Keston 170 Condensing Boiler CL 73 3 Water treatment must be carried out to BS 7593 Treatment of Water Hot Water Central Heating Systems Pump isolating valves must be positioned as close to the pump as possible a 2 7 1 The Keston 170 is suitable for use on open vented water systems with combined feed and vent It is preferable for use on sealed water systems provided the appropriate components required see Section 2 7 2 Sealed Systems are included in the system Any system must be thoroughly flushed clean of grease dirt and debris prior to connection with the boiler A trap should be installed in the flow line to collect any solder or other debris from the installation All water systems must be constructed to comply with requirements of the Local Water Authority Only fully pumped systems can be used gravity systems are strictly not suitable Always use a system complying with the requirements of BS 5449 and BS 6798 The
69. water volume boilers must be maintained so that water is moved through the boiler fast enough so as not to reach boiling temperatures The slower the water moves through the boiler the more heat it will absorb and the higher the temperatures will rise Consequently the pump selected must be adequate to maintain the critical flow of water DETERMINE RADIATION NEEDED ROOM BY ROOM A radiator or convector s ability to deliver heat is related to the water temperature and the rate of delivery to the unit Most systems in the past have been rated at about 80 C Higher efficiencies can be gained from a condensing boiler if ratings published at lower temperatures are used However this is not imperative With normal 80 C ratings used a condensing boiler will still deliver significantly higher efficencies than a non condensing boiler Lower water temperatures in the system tend to increase the efficiency of the boiler and will help assure that the boiler is subjected to a sufficient load to avoid short cycling The Keston boilers are capable of temperatures of up to 80 C but the higher the temperature of the return water the lower the efficiency of the system This is true of all boilers though all non condensing boiler must be kept at higher temperatures to avoid condensation in the boiler which destroys such boilers quickly Materials used in the Keston are made to withstand the condensates corrosive nature Installation amp Servicing Instruction

Keston K170 Installation Manual

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