Keston K340 User Instructions
Contents
1. Installation amp Servicing Instructions Page 32 WD53 0 1999 Chapter 5 Fault Finding The Keston 260 and 340 Condensing Boiler 2 5 7 4 Controls Assembly Installation amp Servicing Instructions Page 33 WD53 0 1998 Chapter 5 Fault Finding SS a M The Keston 260 amp 340 Condensing Boiler 5 7 5 Exploded Diagrams Parts Reference List Casing Assembly Fig 5 7 1 Description Cabinet Frame Name Plate Front Panel Description Heat Exchanger Burner Burner Head Gasket Sight Glass Ignitor Gasket Spark Ignition Electrode Pressure Test Nipple Condensate Trap Boiler Return Thermostat Flue Overheat Thermostat Combustion Test Plug Flow Overheat Thermostat Flow High Limit Thermostat Water Pressure Switch Description Combustion Blower Air Orifice Gas Valve Pressure Test Nipple Low Gas Pressure Switch GC Number Code 4 40 12 Waterway Condensate amp Flue Assembly Fig 5 7 2 GC Number Co2. Example Air inlet uses two one 92 5 sweep elbows Hence maximum length permissible ie a b in figure 2 8 2 20 0m 1 0m 1 0m 18 0m Flue outlet uses one 92 5 sweep elbow Hence maximum length permissible ie c d in figure 7 40 0m 1 0 m total Keston air inlet length 39 0m total air inlet length Figure 2 7 2 Flue amp Air Maximum Length Example Slope Figure 2 7 3 Flue Condensate Drain Point Example Horizontal flue outlet pipework MUST slope at least 2 5 degrees 45 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 ToTeniral 4g Tee Fitting 6 in min Due the low temperature of the flue gases further condensate will form within the flue system Drain points with suitable traps must therefore be incorporated within the flue system at the base of vertical flue sections in excess of 4m These additional condensate drains must be run to discharge as detailed in section 2 10 Such drain points can be formed using standard Keston Composite flue fittings Refer to the example in Figure 2 7 3 Terminations Air inlet terminals must be facing dow
3. 5 7 6 1 6 2 The Keston 260 amp 340 Condensing Boilers Combustion Fine Tuning Handing Over To The User FAULT FINDING Electrical Control Sequence Fault Finding Flow Chart Continuity Checking Module Functional Flow Wiring Diagram Full Electrical Wiring Diagram Full Illustrated Wiring Diagram Exploded Assembly Diagrams SERVICING Pre Service Checks Recommended Routine Service REPLACEMENT OF PARTS General Precautions Access Replacement Procedure Electrical Components Gas Orifice Spark Ignition Flame Detection Electrode Burner Head amp Burner Heat Exchanger Condensate Trap Pressure Gauge Sight Glass HT Ignition Lead Air Orifice SPARE PARTS LISTINGS Page ii Instruction The K n2 4 ndensing Boiler 1 GENERAL INSTRUCTION 1 1 DESCRIPTION The Keston 260 and 340 Condensing Boilers are unique in their concept and design They comprise two boiler modules with individual gas valve fans burners and heat exchanger assemblies The two modules are fully independent in operation and are automatically sequenced to provide optimum load matching In addition firing sequence is regularly rotated to ensure even usage levels While the application for which the boilers were 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 20 metres horizontally or vertically The Keston 260
4. 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 successful and the boiler is operating normally the green run lamp the upper lamp adjacent to the flame symbol lamp will remain illuminated 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 the blower will post purge for 120 seconds and the red lockout lamp will illuminate 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 g Turn of the on off switch for the left hand module and repeat step f for the right hand module h Check for gas soundness between the gas service cocks and connection to each burner manifold 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 C Refill the system usi
5. nominal bore Air Intake Pipe Size nominal bore Max Air Intake Length Max Flue Outlet Length Max Total Flue Outlet and Air Intake Length Type of Gas Flue amp Air Intake Pipe Material kW Btu h kW Btu h kW Btu h kW Btu h mbar in w g l s Ft hr C m ft Bar m mbar in w g mm C l s Ww mm mm mm kg Ibs kg Ibs mm in mm in KESTON 260 84 6 288 650 76 1 259 650 79 5 271 250 82 9 282 850 9 8 3 9 2 19 278 82 00 30 50 100 2 70 3 0 20 0 8 0 3 75 10 to 15 1 6 230V 50Hz 1200 1262 1082 354 165 363 150 330 Rp 2 F Rp 1 25 F 100 4 100 4 20 0 39 0 40 0 KESTON 340 110 375 300 99 0 337 800 104 0 354 800 107 8 367 800 13 0 5 2 2 84 362 82 00 30 50 100 2 70 3 0 20 0 8 0 4 75 10 to 15 2 0 230V 50Hz 1200 1262 1082 354 165 363 150 330 Rp 2 F 40 0 G20 Natural Gas Only Keston Composite Pipe Only 8 4 Optimum Flue Gas CO2 Level 8 4 Destination Countries GB IE GB IE Installation amp Servicing Instructions Page 3 WD53 0 1999 Chapter 2 Boiler Connections The Keston 260 amp 340 Condensing Boilers 2 BOILER LOCATION All dimensions in mm r 7 2 1 DIMENSIONS AND MINIMUM 2 2 2 3 CLEARANCES The boiler must be installed in minimum clearances shown to allow subsequent servicing and safe operation SERVICE CONNECTIONS Gas w
6. 6891 k Gas Supplies BS 6644 i Installation of gas fired hot water boilers of rated input between 60kW and 2MW BS 6880 Central Heating by LPHW BS 7593 Treatment of Water in Hot Water Central Heating Systems Installation amp Servicing Instructions Page 2 Instr The K n2 4 ndensing Boiler CP342 2 Centralised HW Supply IM 2 Purging procedure for non domestic gas installations IM 16 Guidance for installation of gas pipework boosters and compressors for customers premises IM 22 Installation guide for high efficiency condensing boilers Industrial and commercial appliances BS 7593 Treatment of Water in Hot Water Central Heating Systems For Timber Framed Buildings please refer to The Institute of Gas Engineers document IGE UP 7 1998 1 4 PERFORMANCE DATA Max Input Gross CV Max Output To Water 80 60C Flow Return Max Output To Water 60 40C Flow Return Max Output To Water 50 30C Flow Return Burner Setting Pressure Hot Factory Preset Gas Consumption After 10 mins CV of Gas 38 7 MJ m 1038 Btu Ft Max Operating Flow Temp Max Head Open Systems Max Press Sealed System Min Head Open Systems Inlet Gas Pressure Gas Orifice Size Recommended Temperature Differential Required Water Flow Rate Electrical Supply Power Consumption Max Cabinet Height Cabinet Width Cabinet Depth Weight Full Weight Empty Flow and Return Connection Gas Connection Flue Pipe Size
7. Faulty control box Replace N Earth Boiler Y Correct Wiring Set gas rate amp combustion Sections 4 7 and 4 8 Installation amp Servicing Instructions Page 25 WD53 0 1998 Chapter 5 Fault Finding The Keston 260 amp 340 Condensing Boiler 5 3 CONTINUITY CHECKING START Is there 230V at terminals 1 17 amp 18 ls there 230V at the module ON OFF switch both terminals ls there 230V at the module return thermostat both terminals ls there 230V at the module flue protection thermostat both terminals ls there 230V at the gas low pressure switch both terminals ls there 230V at the module water pressure switch both terminals ls there 230V at the flow overheat thermostat both terminals ls there 230V at the flow high limit thermostat both terminals ls there 230V at the module thermal fuse links all terminals To check continuity connect one probe to a neutral and use the other probe to check 230V AC Check external controls and supply Faulty switch Replace Module is up to temperature Allow to cool OR pump not running OR faulty thermostat OR faulty sequence controller Replace Thermostat tripped Check thermostat heat exchanger and combustion Check gas supply to boiler OR faulty switch Replace Check water level in header tank OR system pressure OR faulty switch replace Thermostat tripped Check flow rate re
8. Headers Multiple Boiler Installations Boiler water flows are critical to the operation of the boiler If flow cannot be maintained through the system pipework to meet the minimums required by the boiler the boiler will kettle or even produce steam which can damage the heat exchanger and invalidate the heat exchanger warranty The implementation of a balance header as shown in the above schematics is recommended to ensure adequate water circulation is maintained through the boiler by the integral boiler shunt pumps irrespective of system conditions The size of the balance header is dependant on the number of boilers serving the header A guide to sizing is given below Total Boiler Output Header Diameter up to 100kW 3 up to 200kW 4 up to 300kW 4 5 up to 400kW 5 When assembling a balance header the following design considerations must be observed a Each boiler must have its own flow and return connection to the balance header pipe Common flow and return connections with other boilers will cause reverse circulation effects to occur b The minimum distance between the system flow and return connections is 600mm c A drain off point should be fitted to the base of the header along with cleaning access for sludge removal d The top of the header should be vented 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 di
9. 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 Water treatment must be carried out to BS 7593 Treatment of Water in Hot Water Central Heating Systems Pump isolating valves must be positioned as close to the pump as possible a The Keston 260 and 340 are suitable for use on open vented water systems with combined feed and vent of 32mm nominal diameter b 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 c Any system must be thoroughly flushed clean of grease dirt and debris prior to connection with the boiler A strainer should be installed in the system return line to collect any solder or other debris from the installation d All water systems must be constructed to comply with requirements of the Local Water Authority e 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 f 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 POINT
10. and Keston 340 are designed to be wall hung However floor standing installation can be accommodated by using the optional floor standing frame The Keston module 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 The flue system is room sealed and fan powered The ignition is direct spark and fully automatic The boiler housing is not waterproof and should be installed in a position where it will always be dry Consideration should also be given to the noise levels generated by the combustion fan when in operation Small air intake points are 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 reduce the possibility of products leakage 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 central heating or pumped central heating with combined indirect sanitary hot water Gravity circuits must not be used Forming part of each boiler module 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 Integral module shunt pumps within the appliance cabinet ensur
11. continuity between the live supply from relay to blower and Y neutral through the motor resistance Motor Fan faulty replace z Is the motor overload tripped y i I Motor will cycle rapidly MMOL Motor to co9 Zz ls there wiring continuity through N Identify amp correct break the in line connector to the motor Continued on Sheet 3 The integral sequence control can be temporarily by passed for fault diagnosis purposes by moving the module link wire from module terminal 8 to module terminal 7 Installation amp Servicing Instructions Page 22 WD53 0 1999 Chapter 5 Fault Finding The Keston 260 and 340 Condensing Boiler Continued from Continued from Sheet 2 sheet 1 Does the module ignition sequence start Z Is the fan motor relay stuck Replace Relay Switch off amp if problem Is the module lockout light on persisits replace control box lt Has the module air pressure Faulty control box switch changed over replace Z Are the tubes and connections Correct tube connection to the air pressure switch sound lt g Is the air pressure across the F Air Pressure Switch more than dace Se switeh 4 inches WG zZ Is the air inlet exhaust or condensate pipe blocked Clear Blockage Is the burner blocked Clear Blockage Z Fan faulty changel Is the gas flow rate to the boiler correct zZ Is the gas supply pressurel Ch eck
12. gas supply or atthe Taaa gas valve urn on module gas cock Continued on sheet 4 Fromshget 4 Installation amp Servicing Instructions Page 23 WD53 0 1998 Chapter 5 Fault Finding The Keston 260 amp 340 Condensing Boiler Continued from Continued on Sheet 3 Sheet 3 Is module burner setting pressure as per spec Adjust burner pressure Section 4 7 lt Faulty gas valve or solenoid replace Is the gas valve opening Y zZ Is there 230VAC at the valve when the green module run Y lamp is lit Faulty gas valve or solenoid replace Z Faulty module control box Replace Is there a spark present zZ Is the HT voltage present at the top of the ignition electrode Faulty HT lead or control box Replace lt Is the spark gap 4mm lt Electrode faulty Replace Does the burner ignite zZ Replace Adjust Ignitor Recheck gas output pressure Check HT lead is securely ixed Clean or replace burner Continued on sheet 5 Installation amp Servicing Instructions Page 24 WD53 0 1999 Chapter 5 Fault Finding The Keston 260 and 340 Condensing Boiler Continued from sheet 4 Does flame stop afte 5 to 10 seconds lt Is boielr earthed correctly lt Are live and neutral supply lines crossed at main connection to boiler ls combustion and gas ratel set correctly lt
13. 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 UNDER FLOOR HEATING WEATHER COMPENSATION Both underfloor heating and weather compensating control demand reduced system operating temperatures for some of all of the time the system is operating Traditionally this is achieved by used of mixing valves to reduce flow temperature by blending return water The Keston Condensing Boiler provides increased operating efficiencies at low return system temperature Therefore in the event the Keston boiler is serving only underfloor heating or only weather compensated circuits at any time the boiler flow temperature should be achieved by limiting the boiler temperature and dispensing with the use of a mixing valve 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 95 operating efficiency from a Keston condensing boiler Installation amp Servicing Instructions Page 12 WD53 0 1999 Chapter 3 Installation The Keston 260 amp 340 Condensing Boilers 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
14. Any breakages or damage to the burner mesh indicate the burner must be replaced b 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 C 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 d Remove the condensate trap Section 7 10 and clean by flushing through with clean running water e 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 f Replace the burner head renewing the gasket if necessary and reconnect the gas air supply and the ignition lead Ensure the flanged gas air supply joint is air tight g Turn on the electrical supply to the boiler and allow the boiler to reach operating temperature levels h Visually inspect the burner through the glass spy hole at the burner head a small mirror will prove useful i Recheck the burner pressure by following the procedure detailed in Section 4 7 j Remove the combustion test point plug from the flue pipe This is situated around 150mm 6ins from the bottom o
15. FOR THE KESTON CONDENSING BOILER RANGE Item GC No 74 73 114118 68 375 527 67 147 114 122 84 375 530 86 375 532 97 375 533 99 375 534 142 114 139 136 375 536 183 E01 074 202 185 E01 075 Part Denomination Burner Burner Manifold Gasket Ignitor Gasket Ignitor Sensor Probe Flexible Hose Gasket Boiler Thermostat Flue Thermostat Flow Overheat Thermostat Flow High Limit Thermostat Gas Valve Gasket Gas Multifunctional Control Valve Ignition Control Box Air Pressure Switch HT Ignition Cable Installation amp Servicing Instructions Page 46 WD180 0 99 KESTON CONDENSING BOILERS IMPORTANT KESTON 260 amp 340 INSTALLATION KEY POINTS Read Installation Manual Carefully Ensure that there is at least 9 feet head of water pressure at the top of the boiler Ensure that the boiler s is connected to the system via a low loss balance header 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 13A for the permanent live Ensure that the external controls are configured to form a link between terminals 17 amp 18 to enable boiler Take gr
16. S g These must be fitted at all high points where air will naturally collect and must be sited to allow complete draining of the system Expansion Tank Expansion Pipe A Figure 2 6 1 Minimum Open Vented System 32mm 9ft Height Minimum System flow s Boiler Keston System return s Installation amp Servicing Instructions Page 6 WD53 0 1999 Chapter 2 Boiler Connections The Keston 260 amp 340 Condensing Boilers 2 6 1 Open Vented Systems A typical system is shown in Figure 2 6 1 which includes a combined feed and vent Note the valve between the boiler flow and the open vent is a three way blowdown type valve Note that the minimum static head required is 3m at the top of the system pipework If the cold feed vent is not brought to the low loss header as shown then the pressure loss across the heat exchanger may have to be taken into account when estimating the static pressure Cold feed vent size must comply with BS6644 Although suitable for open vented systems with combined feed and vent arrangements the Keston is a low water content boiler As such any air entrainment within the system water will produce boiler kettling It is therefore recommended if in any doubt to consider the use of sealed systems where possible Safety Valve py q O System flow s Boiler System return s N Expansion ae Vessel Figure 2 6 2 Sealed System 2 6 2 Sealed Systems Sealed s
17. WD53 0 1999 The Keston 260 amp 340 Condensing Boilers KESTON 260 000 Btu h 76 2kW Model 340 000 Btu h 100kW Model Fan Powered High Efficiency Commercial Condensing Gas Boiler Installation And Servicing Instructions Keston 260 Keston 340 PI No 87AU111 GB IE These instructions must be left either with the user or next to the site gas meter Boilers 34 West Common Road Hayes Bromley Kent BR2 7BX Tel 44 0 208 462 0262 Fax 44 0 208 462 4459 e mail info keston co uk http www keston co uk CE 0087 WD53 0 1999 Section 1 h h h Roo The Keston 260 amp 340 Condensing Boilers CONTENTS Description GENERAL INSTRUCTION Description Boiler Schematic Related Documents Performance Data BOILER LOCATION Dimensions amp Minimum Clearances Service Connections Position Electrical Gas Supply Water Systems Flue System Air Supply Compartment Installation Condensate Drainage Under Floor Heating Weather Compensation INSTALLATION OF THE BOILER Wall Mounting Bracket Mounting The Boiler Floor Standing Frame Optional 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 Initial Firing Hot Flushing Checking The Gas Pressure Page i WD53 0 1999 4 7 4 8 5 1 5 2 5 3 5 4 5 5 5 6
18. ain 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 Installation amp Servicing Instructions Page 1 WD53 0 1999 Chapter 1 General Instruction The Keston 260 amp 340 Condensing Boilers 1 3 Fig 1 2 Boiler Layout The condensate is very slightly acidic with a pH level of around 5 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 100mm composite plastic pipe to the outside The temperature of the flue gases are usually around 5 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 calorifier thermostats programmer time clocks and energy management systems RELATED DOCUMENTS The Keston Condensing Boiler must be installed in accordance with the current issue of the Gas Safety Installation and Use Regulations as amended after 1996 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
19. ater air and flue pipe condensation and electrical connections are as shown Gas 1 25 inch BSP female Flow Return 2 inch BSP female 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 hee 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 T 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 27 Figure 2 11 Minimum Clearances 4 s 1 Mean Ppt a i j y a I Tedre airs J J miren iar i amp Fi fi Ling age Sa e ie SE iad ieee oe rT la i ondarme dm EFI J I D Gaa inei Por ETF i i l i
20. ch modules blower b Smooth lighting of each modules burner Cc Check for leakage of gas gas air or combustion products d Check for condensate leaks e Check the colour and appearance of the flame on each module A sky blue flame slightly off the burner gauze is normal The burner itself should appear dark 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 g Check for water soundness h 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 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 6 1 1 Module 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 on the heat exchanger for the left hand module Attach a differential gauge iii Turn on the boiler and wait for the fan to reach full speed Obviously the burner will not light iv The pressure difference should be less than 10 0 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 po
21. ction 7 1 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 7 5 MODULE GAS ORIFICE Fig 5 7 3 item 144 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 iii Unscrew and remove the brass plug from the gas outlet block iv Remove the rubber seal from the injector housing v Insert a flat blade screwdriver into the exposed hole and unscrew the gas injector vi Check the injector is the correct size for the boiler size vii Reassemble Section 7 3 NB Ensure that the injector is screwed fully home vili Reset the gas pressure and combustion See Section 4 Commissioning 7 6 MODULE SPARK IGNITION FLAME DETECTION ELECTRODE Fig 5 7 2 item 67 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 iii Remove the pull off HT lead to the spark ignition electrode iv Remove the burner head Section 7 7 steps iv to vi v Undo the screws to the spark ignition electrode flange located on the burner head and withdraw the spark ignition electrode vi 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 4mm Distances above or be
22. de 114115 77 74 114118 73 114 028 71 375 527 68 114 120 67 114 029 69 90 375 530 84 375 532 86 114 043 101 375 533 97 375 534 99 114 045 88 Air Gas Assembly Fig 5 7 3 GC Number Code 114 131 154 163 375 536 136 114 029 69 114073 134 x 144 Boiler Controls Assembly Fig 5 7 4 GC Number Code 217 E01 074 183 202 205 215 214 114 080 211 Gas Injector Description Sequence Controller Ignition Control Box Air Pressure Switch Electrical Terminal Block Main On Off Switch Module On Off Switch Module Green Run Lamp Module Red Lockout Lamp Pressure Gauge Installation amp Servicing Instructions Page 34 WD53 0 1999 Chapter 6 Servicing The Keston 260 amp 340 Condensing Boilers ee 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 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 Open the front doors by turning the door catches 90 degrees The following items should be observed a Smooth starting and running of ea
23. e each module receives correct water flow when firing 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 1 2 BOILER SCHEMATIC Air is drawn into the boiler through a 100mm composite plastic pipe Each module air flow 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 When the return water temperature is below 55 C part of the water vapour in the combustion products will condense inside the heat exchanger thus increasing the boiler efficiency further 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 dr
24. eat 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 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 Gravity circuits are not allowed
25. ectors must be made and sealed with solvent cement suitable for Keston Composite pipes Installation amp Servicing Instructions Page 11 WD53 0 1999 smn 2 Boiler Connections The Keston 260 amp 340 Condensing Boilers 2 8 2 9 2 10 2 11 External wall faces and any internal faces of cavity walls must be made good AIR SUPPLY The Keston is a room sealed appliance and therefore does not require purpose provided ventilation to the boiler room for combustion air COMPARTMENT INSTALLATION The casing temperatures of the Keston 260 and Keston 340 are very low Due to this fact no compartment ventilation 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 28mm 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 building 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
26. ensible joints and the gas inlet pressure 20 mbar required If all joints are sound and the gas inlet pressure is satisfactory set the gas pressure Full details of this procedure are given in Section 4 6 Checking The Gas Pressure This will ensure that combustion is good enough to allow combustion fine tuning to take place Combustion Fine Tuning It is advisable on all installations that the combustion quality is checked by measuring the carbon dioxide CO2 or oxygen O3 level This procedure is detailed in Section 4 7 Combustion Fine Tuning Badly tuned combustion will lead to reduce the life of the boiler and invalidate the warranty Installation amp Servicing Instructions Page 16 WD53 0 1999 Chapter 4 Commissioning The Keston 260 amp 340 Condensing Boilers 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 INITIAL FLUSHING All waterways within the Keston are either copper bronze or high alloy stainless steel As a result standard water treatment chemicals for conventional central heating boilers are suitable 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 l
27. er thermostat Section 7 4 2 vii 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 viii Remove the condensate trap Section 7 10 ix Remove the pressure gauge phial located next to the drain off tap x Disconnect the flow to the heat exchanger at the union on the heat exchanger flow manifold xi Undo the nut and olive of the isolating valve fitted directly on the heat exchanger return pipe xii Remove the nut fixing the strap retaining the base of the heat exchanger and pull out the strap by unhooking it from its fixing behind the heat exchanger xili Remove the allen screw securing the top of the heat exchanger to its mounting bracket xiv Remove the heat exchanger assembly by pulling forward at the top and lifting up and out of the appliance xv Cut the olive from the heat exchanger return pipe and remove the compression nut Xx Reassemble Section 7 3 xxi Recommission Section 4 Commissioning 7 9 CONDENSATE TRAP Fig 5 7 2 item 90 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 iii Disconnect the condensate line from the base of the heat exchanger iv Disconnect the condensate line from the base of the flue assembly v Disconnect the condense lines from the projection of the condensate trap from the base of the cabinet vi Withdraw the condensate tra
28. f the flue elbow at its connection to the heat exchanger k Using an approved combustion tester sample the flue products via the combustion test point CO levels of between 8 2 and 8 5 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 l Replace the combustion test point plug m Check all joints for soundness up to the gas burner n Repeat the procedure for the other module Installation amp Servicing Instructions Page 36 WD53 0 1999 Chapter 7 Replacement Of Parts The Keston 260 and 340 Condensing Boilers eC 7 REPLACEMENT OF PARTS INDEX 7 0 GENERAL 7 1 PRECAUTIONS 7 2 ACCESS 7 3 PROCEDURES GENERAL 7 4 ELECTRICAL 7 4 1 ON OFF SWITCH 7 4 2 BOILER THERMOSTAT 7 4 3 FLOW OVERHEAT FLOW HIGH LIMIT amp FLUE PROTECTION THERMOMSTATS 7 4 4 WATER PRESSURE SWITCH 7 4 5 IGNITION CONTROL BOX 7 4 6 AIR PRESSURE SWITCH 7 4 7 COMBUSTION BLOWER 7 4 8 GAS CONTROL VALVE 7 4 9 GAS LOW PRESSURE SWITCH 7 5 GAS ORIFICE 7 6 SPARK IGNITION FLAME DETECTION ELECTRODE 7 7 BURNER HEAD amp BURNER 7 8 HEAT EXCHANGER 7 9 AIR FILTER 7 10 CONDENSATE TRAP 7 14 PRESSURE GAUGE 7 12 SIGHT GLASS 7 13 HT IGNITION LEAD 7 14 AIR ORIFICE Installation amp Servicing Instructions Page 38 WD53 0 1999 cine 7 Of Parts The Keston 260 amp 340 Condensing Boilers 7 0 GENERAL The following must always be carried
29. i Disconnect the flexible air intake hose from the air gas manifold Fig 5 7 3 item 164 iv Unscrew the air orifice grub screw Fig 5 7 3 item 140 to release the air orifice v Lift the air orifice from its 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 43 WD53 0 1999 Chapter 8 Spare Parts Listings The Keston 260 amp 340 Condensing Boilers ee 8 SHORT SPARE PARTS LIST Item GCNo Part Denomination Item GCNo Part Denomination 74 Burner 73 114 118Burner Manifold Gasket 68 375 527 Ignitor Gasket 67 Ignitor Sensor Probe 110 Flexible Hose Gasket 84 375 530Boiler Thermostat 86 375 532Flue Thermostat 97 375 533Flow Overheat Thermostat Installation amp Servicing Instructions Page 46 WD53 0 1999 Chapter 8 Spare Parts Listings The Keston 260 amp 340 Condensing Boilers Item GC No Part Denomination Item GC No Part Denomination 99 375 534Flow High Limit Stat 142 375 535Gas Valve Outlet Gasket 136 375 536Gas Valve 147 114 122Flexible Hose Gasket 183 E01 074 Ignition Control Box 202 Air Pressure Switch 185 E01 075 HT Ignition Cable Installation amp Servicing Instructions Page 46 WD53 0 1999 Chapter 8 Spare Parts Listings The Keston 260 amp 340 Condensing Boilers SHORT SPARE PARTS LIST
30. ink 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 C Connect the system to the boiler and fill in accordance with Section 2 6 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 INITIAL FIRING Important Checking the gas pressure to the pre mix burners requires a special procedure outlined below which must be carried out a Purge the gas supply in accordance with BS 6891 amp IM 2 b Vent the water system Important The Keston heat exchanger module consists of a single coil which can trap an air pocket Great care must be taken to ensure that water fl
31. int A to C replacing the screw on point A 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 between 9 5 mbar and 13 5 mbar lowest value represents new appliance 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 Repeat the procedure for the right hand module xiv Remove the pressure gauge tube and refit the screw xv Open the gas service cock Installation amp Servicing Instructions Page 35 WD53 0 1999 Chapter 6 Servicing The Keston 260 amp 340 Condensing Boilers ee Fl Pressure Test Pressure Test Point A Point B o gt Pressure Test Heat Point C Exchanger On Shell Combustion Test Point Burner Heat From Above iS Ais Over heat Ther mostat Fig 6 11 Module Pressure Test Point Locations 6 2 Recommended Routine Service The procedure detailed below should be carried out on each boiler module in turn The integral boiler controller ensures both modules are loaded evenly over a year of operation a 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
32. ir inlet must be Keston Composite pipe of an internal diameter not less than 100mm Suitable pipe and fittings can be obtained by Keston Boilers Ltd via its appointed distributors Both flue outlet terminal and air inlet terminal are supplied and are illustrated in Figure 2 7 1 Although the flue outlet and air inlet terminals are identical great Figure 2 7 1 care must be taken to ensure that Terminal Design the air intake terminal is positioned facing downwards or in such a way as to ensure rain cannot enter the air intake pipework Boiler damage due to water entry through the air intake pipework is not covered under the appliance warranty 2 7 2 Minimum amp Maximum Lengths The flue outlet and air inlet pipes must have lengths of at least 1m each The maximum lengths of both air inlet pipe and flue outlet pipe when no bends are used are as detailed below Minimum Flue Length 0 5m Minimum Air Intake Length 0 5m Maximum Air Inlet Length 20 0 m Maximum Flue Outlet Length 39 0 m Maximum Combined Air Inlet 40 0 m and Flue Outlet Length 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 Installation amp Servicing Instructions Page 9 W D53 0 1999 2 7 3 2 7 4 Chapter 2 Boiler Connections The Keston 260 amp 340 Condensing Boilers
33. ke 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 blower shelf 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 8 Module Gas Control Valve Fig 5 7 3 item 136 i i ii 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 switch at its connection to the gas control valve body Installation amp Servicing Instructions Page 40 WD53 0 1999 aan 7 ieee Of Parts ___The Keston 260 amp 340 Condensing Boilers xii Reassemble Section 7 3 xiii Reset the gas rate See Section 4 Commissioning 7 4 9 Module Gas Low Pressure Switch Fig 5 7 3 item 134 i Isolate the appliance Se
34. king note of the correct positions vi Unscrew the pressure switch vii Reassemble Section 7 3 viii Refill the system See Section 4 Commissioning 7 4 5 Module Ignition Control Box Fig 5 7 4 item 183 i ii iii iv v vi 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 Reassemble Section 7 3 7 4 6 Module Air Pressure Switch Fig 5 7 4 item 202 i ii iii iv v vi 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 fixed behind the lower mounting screw 7 4 7 Module Combustion Blower Fig 5 7 3 item 154 NB i ii iii vi v vi 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 in the blower motor connection box Remove the allen screws fixing the air inta
35. l 5 uy nie Meat Firg hos g E We r Tigi Fam archaeal iA a tL F T Gni 14 H E G PI Fia Agr Figure 2 1 2 Installation amp Servicing Instructions Page 4 WD53 0 1999 Chapter 2 Boiler Connections The Keston 260 amp 340 Condensing Boilers a 2 4 2 5 Before locating the boiler near a living space consider whether the sounds generated by the boiler will be objectionable The boiler may be located within a cupboard enclosure to reduce noise levels if located within a living space ELECTRICAL 2 4 1 Electrical Connections The boiler must be connected to 230V 50Hz supply controls as follows Mains Connection rated at 10A Terminal 1 LIVE Terminal 2 NEUTRAL Terminal 3 EARTH On Off User Control Link volt free external control Terminal 17 Terminal 18 Remote Lockout Signal 230V Terminal 19 Module 1 Terminal 20 Module 2 NB External monitoring controls must be configured to ignore signal unless present for more than 5 seconds Main System Pump optional pump on when boiler enabled Terminal 4 Live Terminal 6 Neutral Terminal 7 Earth Wiring external to the boiler must be in accordance with current I E E wiring regulations and local regulations The method of connection to the mains electricity supply must facilitate complete electrical isolation of the boiler complying with the requirements of BS 1363 There must be only one common method of isolation f
36. low 4mm will affect ignition performance If necessary gently bend the electrode taking care not to damage the ceramic insulator 7 7 MODULE BURNER HEAD amp BURNER Fig 5 7 2 items 72 amp 74 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 iii Remove the pull off HT lead to the spark ignition flame detection electrode head iv Remove the two allen screws fixing the flange gas air mixture pipe connection to the burner head v Remove the five allen screws fixing the burner head to the top of the heat exchanger vi Withdraw the burner amp burner head from the top of the heat exchanger vil Unscrew the burner from the burner head taking care not to damage the burner mesh grip the burner on the collet only viii Reassemble Section 7 3 NB When reassembling inspect any gaskets for damage and replace if necessary Set the spark gap as detailed in Section 7 6 ix Reset the gas rate see Section 4 Commissioning Installation amp Servicing Instructions Page 43 WD53 0 1999 Chapter 7 Replacement Of Parts The Keston 260 and 340 Condensing Boilers EES Sa 7 8 MODULE HEAT EXCHANGER Fig 5 7 2 item 77 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 iii Shut of the water supply to the appliance iv Remove the burner head Section 7 7 v Drain the system to below the level of the appliance using the drain off tap at the base of the heat exchanger vi Remove the boil
37. m to BS6500 Table 16 material code HO5VV F 3 The permanent live supply connection may be via a 10 amp fused double pole switch serving only the boiler 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 supply cable s must be connected to the main terminals as follows Terminal 2 N Blue wire Neutral for 10A permanent supply Terminal 1 L Brown wire Live 10A permanent supply Terminal 3 E Yellow Green Wire Earth Terminal 17 amp 18 On Off User controls volt free control link The pump cable if used must be connected to the pump terminals as follows Terminal 6 N Pump neutral wire blue Terminal 4 L Pump live wire brown Terminal 7 E Pump earth yellow green NB The system circulating pump should not have a locked rotor current rating exceeding 2A if powered via Terminal 4 of the boiler main terminal block Ensure connection is made such that if the cable slips in its anchorage the current carrying conductors become taut before the earthing conductor EXCHANGING A BOILER Before removing an existing boiler 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 f
38. must be explained If the a red light only is illuminated for more than 10 seconds this means that the module has failed to light Turn off the module 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 module must be isolated and a Service Engineer called in to rectify the fault C Advise that a reduction in 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 Hand over User Instructions gt Installation amp Servicing Instructions Page 19 WD53 0 1998 Chapter 5 Fault Finding The Keston 260 amp 340 Condensing Boiler Ree 5 1 5 FAULT FINDING ELECTRICAL CONTROL SEQUENCE When the power supply is established to the boiler and the main boiler on off switch is in the on position the main on off switch will be illuminated Subsequently when the external controls are calling for heat power will be fed back to the boiler connection strip at terminal 18 If the integral sequence controller detects the boiler flow temperature is below the required set point one of the modules will be enabled causing that modules on off switch subject to being in the on position to be illuminated P
39. ng a quality water treatment such as Fernox MB1 For sealed systems fill to the required Initial Design Pressure CHECKING THE GAS PRESSURE With each module running measure each burner pressure at the module burner Fig 4 6 pressure test nipple MODULE GAS VALVE The gas setting is factory adjusted to within the required range and should not normally need re adjustment If the reading is incorrect then check such factors as soundness of the air and flue pipe joints Burner pressure and the gas inlet pressure 20 mbar Adjustment required If all joints are sound and the gas inlet pressure is satisfactory remove the Burner pressure brass dust cap covering the burner test nipple iy pressure adjustment screw on the gas valve See fig 4 6 Set the gas pressure to the required value as stated on the databadge 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 Installation amp Servicing Instructions Page 18 WD53 0 1999 Chapter 4 Commissioning The Keston 260 amp 340 Condensing Boilers 47 4 8 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 be
40. nwards and positioned to ensure only fresh air is drawn into the boiler The air terminal must be located outside of the Drawing of combustion air directly from a ventilated boiler room will invalidate the heat exchanger warranty The air inlet terminal must face downwards to prevent entry of rain into the air intake pipework Installation amp Servicing Instructions Page 10 WD53 0 1999 Chapter 2 Boiler Connections The Keston 260 amp 340 Condensing Boilers a The flue outlet terminal is designed to face outwards but can if desired be adapted to face in any direction BUT must not be directed in the region of the air inlet Where the air and flue terminals are located in close proximity the flue terminal should be located above the level of the air inlet terminal 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 Suitable terminal guards can be obtained from Tower Flue Components Ltd or its distributors 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 locati
41. o to a lockout state red lamp illuminated only Once the gas supply has been resumed the module can be reset by turning the module off and then on again on the boiler control panel 7 The module 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 Dependant on the system loading the integral boiler sequence controller may enable the other module at any time subject to that modules on off switch being in the ON position The sequence of operation shall be identical to that described above 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 20 WD53 0 1999 Chapter 5 Fault Finding The Keston 260 and 340 Condensing Boiler 5 2 FAULT FINDING FLOW CHART Is main on off switch light on Z Is main on off switch n on p
42. on 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 Dimensions mm Flue Air Terminal Inlet A Below or beside openable window air brick 500 50 etc 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 7 4 Minimum Flue Terminations amp Air Inlet Dimensions 2 7 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 7 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 7 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 pipe work must be adequately supported All joints other than push on or plastic compression conn
43. or the boiler and its control system The appliance must be connected to the 10A 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 controls GAS SUPPLY A gas meter should be connected to the service pipe by the local gas supplier 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 Gas consumption is given in Section 1 4 The boilers are for use with NATURAL GAS G20 ONLY Minimum Maximum Natural Gas Pressure Natural gas pressure before the gas valve must be maintained at between 17 5 mbar 7 in WG and 22 5 mbar 9 in WG while both modules are 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 1 25 in 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 ignition failures Ensure gas supply pipe work is adequately sized for the length of run from the meter to the boiler Installation amp Servicing Instructions Page 5 WD53 0 1999 nn 2 Boiler Connections The Keston 260 amp 340 Condensing Boilers 2 6
44. osition ls there 230VAC betw een connector strip terminals 1 and 2 lt Faulty switch neon Replace switch Set external controls to on and turn off other module u Is there 230VAC at terminal 18 lt Is the module switched on lt Faulty switch neon replace switch Continued on Sheet 2 Is module amber switch light on Apply power to boiler Check external power supply Check external controls Switch on module Installation amp Servicing Instructions Page 21 WD53 0 1998 Chapter 5 Fault Finding The Keston 260 amp 340 Condensing Boiler Continued from sheet 1 Is the module fan running Zz Boiler flow is too hot Is the integral sequence controller N Adjust set point higher or calling the module on allow to cool or faulty sequence control lt Module return is too hot Is the module return N All thermostat closed OW ook faulty thermostat replace lt Is there 230VAC between control box pins 10 amp 2 and between N pins 10 amp 1 Check continuity see section 5 3 Fault hose connection to Y APS OR Faulty APS Replace lt Is the air pressure switch stuck in the NO position Zz Is there 230VAC between control box pin 6 and neutral Control box faulty zZ lt y Relay not secure in socket Is the fan motor relay operating 7 N Or relay faulty replace lt Is there
45. out by a competent qualified person 7 1 PRECAUTIONS i Always switch off the mains electricity supply ii Gain access to the appliance Section 7 2 and turn off the gas supply at the appliance service cock WARNING Parts of the boiler internal wiring will remain live even after turning the boiler ON OFF switch to the OFF position Shut off the power supply at the isolating switch before working on the appliance 7 2 ACCESS i Open the front doors by turning the locating catches 90 degrees to release 7 3 REPLACEMENT PROCEDURES i Always replace in the reverse order unless otherwise stated ii Electrical connections must be remade in accordance with the Wiring Diagram Section 5 5 iii Test the soundness of any gas carrying or water carrying joint broken during the service procedures 7 4 ELECTRICAL COMPONENTS 7 4 1 Master and Module On Off Switches Fig 5 7 4 items 214 amp 215 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 7 4 2 Module Boiler Return Thermostats Fig 5 7 2 item 84 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 Unscre
46. ove all plastic debris and burrs when installing air intake piping Plastic filings caused by cutting Keston Composite plastic pipe must not be allowed to be drawn into the 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 3 5 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 Installation amp Servicing Instructions Page 13 WD53 0 1999 Chapter 3 Installation The Keston 260 amp 340 Condensing Boilers 3 6 3 7 3 8 a 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 boiler If the boiler stays put then it is imperative that the front doors are closed 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 b Drill the two holes in the wall ceiling preferably using a core drill c Always thoroughly deburr all pipes and most important remove shavings from within the pipe d Assemble the pipework from the boiler connections to the exit from the first wall ceiling remount the boiler if
47. ow has been established through the heat exchanger 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 Turn both the integral gas service cocks to ON Turn on the electrical supply setting any external controls to call for heat e Set the main boiler On Off switch to ON and adjust the set point temperature to a value above actual flow temperature adjustment is made by holding in the press button located below the control knob and adjusting the control knob until the required set point temperature is displayed Releasing the press button will cause the control knob to be ineffective and the display to register actual flow temperature 2 op Installation amp Servicing Instructions Page 17 WD53 0 1999 Chapter 4 Commissioning The Keston 260 amp 340 Condensing Boilers 4 5 4 6 f Set the left hand module on off switch to ON The amber light will illuminate on the On Off switch the red lockout light will illuminate for approximately 2 seconds The module blower and pump will start and after about 15 seconds a spark will light gas at the main burner 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 be illuminated indicating successful ignition
48. p vii Mop up any spilled condensate viii 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 condensate hose to the base of the heat exchanger 7 11 PRESSURE GAUGE Fig 5 7 4 item 211 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 Installation amp Servicing Instructions Page 42 WD53 0 1999 mines 7 Of Parts The Keston 260 amp 340 Condensing Boilers 7 12 MODULE SIGHT GLASS Fig 5 7 2 item 71 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 7 13 MODULE HT IGNITION LEAD Fig 5 7 4 item 185 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 7 14 MODULE AIR ORIFICE Fig 5 7 3 item 163 i Isolate the appliance Section 7 1 ii Gain access Section 7 2 ii
49. p Servicing Instructions Page 28 WD53 0 1999 Chapter 5 Fault Finding The Keston 260 and 340 Condensing Boiler 5 6 ILLUSTRATED WIRING DIAGRAM 6 w c0 lt gt H0 30 Installation amp Servicing Instructions Page 29 WD53 0 1998 Chapter 5 Fault Finding The Keston 260 amp 340 Condensing Boiler a e s 5 7 Exploded Assembly Diagrams 5 7 1 Casing Assembly Installation amp Servicing Instructions Page 30 WD53 0 1999 Chapter 5 Fault Finding The Keston 260 and 340 Condensing Boiler ee 5 7 2 Waterway Condensate amp Flue Assembly Installation amp Servicing Instructions Page 31 WD53 0 1998 Chapter 5 Fault Finding The Keston 260 amp 340 Condensing Boiler Eeee eee 5 7 3 Air Gas Assembly
50. r Details are provided in Chapter 2 Section 2 10 Condensate Drainage Connection 22 mm plastic pipe WATER SYSTEM Connect the flow and return pipework to the boiler Details of system requirements are given in Chapter 2 Section 2 6 Water Systems Connections 2 BSP F GAS SUPPLY Connect the gas supply to the appliance Details of gas supply requirements are given in Chapter 2 Section 2 5 Gas Supply Supply of adequate gas pressure with the boiler running is critical to ensure reliable operation of the boiler Connections 1 25 inch BSP F Installation amp Servicing Instructions Page 14 WD53 0 1999 Chapter 3 Installation The Keston 260 amp 340 Condensing Boilers 3 9 3 10 ELECTRICAL SUPPLY The entry point s for the electrical supply cable s is in the base of the appliance see Section 2 2 Service Connections fig 2 1 2 via two cord grip bushes Feed the cable s through its 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 Supply wiring should be in PVC insulated cable not less than 1 0mm to BS 6500 Table 16 material code HO5VV F Pump wiring from the boiler pump connection should be in 3 core PVC insulated cable not less than 0 5m
51. 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 6 Condensate Drainage Make the final connection of flue and air pipe to the boiler using push on plastic 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 connecting couplings e Using the same methods drill any further holes always covering existing pipework cut and assemble the pipework f From outside complete the two terminations See Section 2 7 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 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 boile
52. rovided all module temperature thermostats and pressure switches are closed power will be fed to pins 1 amp 2 on the module ignition control box initiating the following sequence 1 The module 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 and extinguish the red lockout lamp 4 After a pre purge period of about 15 seconds the module 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 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 supply 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 module will make two further attempts to ignite at intervals of approximately 1 minute and will then g
53. set thermostat OR faulty thermostat Replace High w ater temperature OR faulty thermostat Replace High cabinet temperature Check all joints for product leakage reaplce thermal fuse link s The sequence controller can be temporarily by passed by moving the link between terminals 8 and 9 on the module terminal block to terminals 7 and 9 Installation amp Servicing Instructions Page 26 WD53 0 1999 Chapter 5 Fault Finding The Keston 260 and 340 Condensing Boiler 5 4 MODULE FUNCTIONAL FLOW WIRING DIAGRAM Main On Off Switch 230V 50Hz Sequence Controller Blower Return Module nela Thermostat Eai ON OFF ES Switch i VY T aie l 7 Modul Lockout Shun Relay Pump Flue Overheat Thermostat Ea Coil Low Gas Pressure Switch Ea Low Water Pressure Switch Lockout Relay Flow Overheat Thermostat Ea Flow High Limit Ther mostat Pe a Thermal Fuse Links Ea Air Press RAM CONTROL BOX Switch Cy Run OS Lamp EMC Filter Installation amp Servicing Instructions Page 27 WD53 0 1998 Chapter 5 Fault Finding The Keston 260 amp 340 Condensing Boiler ee 5 5 FULL ELECTRICAL WIRING DIAGRAM 7 l Elise Ses sere Hlas Ten T Ss i i By lo I i aa Pe HH lt Installation am
54. ssolved 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 Y strainer on the system return s will trap any debris left in the system The boiler guarantee does not cover heat exchanger failure due to debris abrasion within the system Installation amp Servicing Instructions Page 8 WD53 0 1999 Chapter 2 Boiler Connections The Keston 260 amp 340 Condensing Boilers r 2 6 7 Pump Selection The Keston 260 and Keston 340 boilers are supplied complete with integral boiler shunt pumps However these pumps are sized purely to provide adequate flow rate through the boiler at the pressure drop caused by the boiler itself No allowance has be provided in the shunt pump size for system resistance A system pump s should therefore be selected sized to provide the required system flow rate at the pressure drop created by the system index circuit 2 7 FLUE SYSTEM 2 7 1 Design Individual air supply and flue outlet pipes are used The material used for flue outlet amp or a
55. st 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 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 5 CO for natural gas To measure CO levels in the Keston boiler remove the 1 8 plug from the flue outlet pipe inside the boiler item 101 fig 5 7 2 Insert the probe of a combustion analysis meter and sample the gases as instructed in the test equipments 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 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
56. 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 All dimensions in mm a Place the bracket on the wall horizontally with the pre drilled holes at the bottom b Drill through the centre hole of 453 a E the bracket plug the hole and fix in position c 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 l marked Plug these holes e Screw the bracket to the wall 346 using screws of an appropriate size for the wall type No 12 x 2 inch wood screws normally k 553 gt suffice 3 2 MOUNTING THE BOILER Figure 3 1Wall Mounting Fixing Locations a Using the detachable side lift handles supplied or via winch lift and locate the upper rear lip on the boiler to the boiler wall bracket b Move the boiler sideways to centralise the boiler on the bracket 3 3 FLOOR STANDING FRAME OPTIONAL If the optional floor standing frame is selected the frame should first be assemble and secured firmly to the plant room floor Suitable assembly instructions are included with the floor standing frame pack Lift the boiler and lower into position onto the frame 3 4 ASSEMBLY PRACTICE Rem
57. ully 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 The guarantee provided with the Keston 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 Installation amp Servicing Instructions Page 15 WD53 0 1999 Chapter 3 Installation The Keston 260 amp 340 Condensing Boilers 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 should not normally need re adjustment If the reading is incorrect then check such factors as soundness of the air and flue pipe joints pressure s
58. w the two retaining screws and remove the thermostat 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 mounting surface This combined with fitting the new thermostat tightly to the mounting surface ensures a good contact 7 4 3 Module Flow Overheat Fig 5 7 2 item 97 Flow High Limit Fig 5 7 2 item 99 amp Flue Protection Thermostats Fig 5 7 2 item 86 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 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 thermostat tightly to the plate ensures a good contact 7 4 4 Module Water Pressure Switch Fig 5 7 2 item 88 i Isolate the appliance Section 7 1 ii Shut off the water supply to the appliance iii Gain access Section 7 2 Installation amp Servicing Instructions Page 43 WD53 0 1999 Chapter 7 Replacement Of Parts The Keston 260 and 340 Condensing Boilers ee iv Drain the system to below the level of the appliance using the drain off tap at the base of each heat exchanger v Remove the push on connectors from the water pressure switch ta
59. ystems must be designed in accordance with BS 6644 and BS 7074 Pti A typical sealed system is shown in Figure 2 6 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 on the basis of the total system volume and initial charge pressure The vessel must be positioned as shown in figure 2 6 2 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 The installation must be designed to work with flow temperatures of up to 110 C Installation amp Servicing Instructions Page 7 WD53 0 1999 aan 2 Boiler Connections The Keston 260 amp 340 Condensing Boilers 2 6 3 2 6 4 2 6 5 2 6 6 All components of the system including the heat exchanger of any calorifiers used 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 DIRECT CYLINDERS MUST NOT BE USED Further guidance is provided in BS 1394 Balance
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