Thermo 90 Thermo 90 S
Contents
1. Motor Combustion air fan Motor Circulation pump Motor Vehicle blower Standard timer 1531 for pre timed operation Fig 7 4 Circuit Diagram Thermo 90 S 12 and 24 V German Version with 7 Day 3 Program digital timer THERMO 90 90 S 8 Servicing 8 1 General This section describes the servicing procedures that may be performed with the heater installed 8 2 Work on the Heater Prior to performing any work it is mandatory to disconnect the vehicle battery main lead As long as the heater is in operation or in run down the battery main supply must not be disconnected due to the danger of overheating and resulting in a response of the overheat protection When performing extensive repairs on the heater a complete removal is advisable After work on the heating circuit a coolant mixture consisting of water and anti freeze must be replenished in accordance with manufacturer instructions followed by a careful bleeding of the heating circuit When performing repairs requiring a relocation of the installation position the relevant installation instructions and the vehicle specific installation proposal have to be observed 8 3 Work on the Vehicle ACAUTION In the vicinity of the heater a temperature of 130 C 266 F must not be exceeded under any circumstances e g during body paint work 8 4 Heater Test Run WARNING The heater must not be operated not even with tim2. 9 6 9 2 9 TL Removal xs bsec UR ARMS Ded d act d A 9 6 9 9 5 2 Installation t eX ot eed el eee ne b o one eee Soo uode e 9 6 9 2 6 Replacement of Burner Flame Sensor and Glow Pin 9 7 9 2 3b Ti OIOV ius o Medio esie dente ue dou den dM pda Sod RECS SIM IUS eui 9 7 9 2 6 2 InistallallOon i Seb PET bare var 9 7 9 2 7 Replacement of Burner Head 9 9 S ob Removal eana edat ath qui UR E rae 9 9 9 272 stella ue a Gok ot SOR ap 24 9 9 9 2 8 Replacement of Heat Exchanger 9 10 eco Base dare ent E Gee 9 10 9 9 9 2 J nstallati Roca Rood Be ee eae RR Faltas goes abo s 9 10 90 90 5 1 Introduction 1 1 Scope and Purpose This repair shop manual is intended to support familiarized personnel in the repair of Thermo 90 and Thermo 90 S coolant heaters The coolant heater may only be operated with the specified fuel Diesel 1 Diesel 2 Arctic grade Kerosene and certain military spec fuels The coolant heater may only be operated within the specified operating voltage range designated by type 1 2 Meaning of Warnings Cautions and Notes Warnings Cautions and Notes in this manual have the following meaning A WARNING This he
3. PLAT C ROT gt FOE o CR A RR 8 7 9 Repair 9 1 SRST als sas fa 3 cca edere d em 9 1 9 1 1 Work on Components after Disassembly 9 1 Gleanings een SE In OR Ese atta ethan ethene Biase 9 1 9 d 1 2 eR aAA SQQ ER S 9 1 9 2 Disassembly and Assembly 9 2 9 2 1 Electrical Connections Fig 9 1 9 2 9 2 1 1 Disconnecting Electrical Connections Connection 1 9 2 9 2 1 2 Making Electrical Connections 9 2 9 2 2 Replacement of Circulation Pump 9 3 26 DIL UE 9 3 9 2 2 2 Installation ou note a hard Syed RU eye hae ohne TA EUER e Ses 9 3 9 2 3 Replacement of Temperature Limiter 9 4 9 9 3l REMOVAL va doy s P pad hos EY BOY s aon ats 9 4 9 23 22 euo RUE RES iet Tet daten etsi em EM S d t s 9 4 9 2 4 Replacement of Temperature 9 4 9 29 41 HeroVal itu ea nubere te Ree E OUI EU Sow sce made 9 4 9o 0 27 instalation rap Eco oe o eo AE MOOR 9 4 9 2 5 Replacement of Combustion Air Fan
4. Jebasto Feel the drive Coolant Heater Thermo 90 Thermo 90 S Workshop M anual TuERMO 90 90 S TABLE OF CONTENTS Table of Contents 1 Introduction 1 1 SCOPE ANd PUIDOSO ess bx SP CIE oye A Sea ee ERES Ad 1 2 Meaning of Warnings Cautions and Notes 1 3 Additional Documentation to be 1 4 General Safety Regulations and Information 1 4 1 General Safety Notes 1 5 Corrections and Improvements 2 General Description 2 1 Air P pU 2 2 Heat Exchanger edes dA A ERA S VE ee 2 3 Temperature Sensor eb ete eq ro RE nb EN E TR ce 24 Temperat re Limiter eue n dude Oot cr ten xn lume wee 2 5 B rher Irisert 2 s debet ee Aad Ra ed ee ee ero dere Ce dex 2 6 Cl wee in ake Aad EST 2 7 Flame Sensor e cred o con de Coe S oet m itc ake 2 8 Combustion TUDE otto toni dau dada SLICE d Een VR S ee 2 9 Circulation PUMP Sad e Le se oA Kan Ea AE air e 2 10 Control UNT t 1 roe o wets ie nd e aub adde qa de e dr e ebd 24t Fuel Dosing PUMP ess nae Deo ERRORES I SE
5. CO2 in exhaust permissible operating range 10 12 0 Vol CO2 setting values at approx 68 F and geographical height above SL 1640 ft 3280 ft 10 6 11 3 Dimensions of heater Tolerance 0 11 in Length 12 2 14 0 in Width 05 24 in Height 08 66 in Weight 9 Thermo 90 S with control unit mounted on heater 10 5 Ib 4 TECHNICAL DATA 4 Technical Data Metric Measure As long as no threshold values are given the following technical data is understood to include tolerances of 10 usual for heaters at an ambient temperature of 20 and at nominal voltage and conditions Coolant Heater Type Operation THERMO 90 90 S Electrical Components Control unit combustion air fan motor and fuel dosing pump glow pin control switch and timer are either of the 12V or 24V type The components temperature limiter temperature sensor and flame sensor are identical in the 12V and 24V units Thermo 90 90 S Thermo 90 90 S Gasoline Diesel BW 80 DW 80 Mark of conformity S231 232 Heater type Coolant heater with Ferro Tec Technology Heat output Maximum Control range 9 1 kW 2 0 kW 7 6 kW 1 8 kW 7 6 kW Type of fuel Gasoline Diesel 1 2 and Arctic Fuel consumption Maximum Control range 1 1 l h 0 25 I h 1 0 I h 0 19 l h 0 9 I h Rated voltage 12 Volt 12 or 24 Volt Operating voltage range 10
6. Remove circulation pump see 9 2 2 1 Remove temperature limiter see 9 2 3 1 Remove temperature sensor see 9 2 4 1 Remove combustion air fan see 9 2 5 1 Remove burner flame sensor and glow pin see 9 2 6 1 Remove burner head see 9 2 7 1 Remove connector and connector housing Perform procedures on components after disassembly see 9 1 1 ON THERMO 90 90 S 9 2 8 2 Installation 1 Clip connector housing onto heat exchanger and engage connector in connector housing Install burner head see 9 2 7 2 Install burner flame sensor and glow pin see 9 2 6 2 Install combustion air fan see 9 2 5 2 Install temperature sensor see 9 2 4 2 Install temperature limiter see 9 2 3 2 Install circulation pump see 9 2 2 2 Install heater see 8 7 1 2 ev OND OP Rev 03 2000 907400 Webasto Thermosystems Inc North America 3333 John Conley Drive Lapeer MI 48446 Phone 810 245 2400 Toll free 800 HEATER 1 Fax 810 664 7720 Technical Assistance Hotline USA 800 555 4518 Canada 800 667 8900 Wwww webasto com
7. ET Deutsch connector and blower interlock wiring with The circuit diagrams Fig 7 2 and 7 4 show possible Deutsch connector North American enclosure amp circuits of the Thermo 90 heater with compact kits see Fig 7 3 N e with 7 Day 3 Program digital timer wiring without with standard switch and harness wiring using Deutsch connector German version see Fig 7 5 Deutsch connector and blower interlock wiring with Deutsch connector North American enclosure amp Fig 7 1 shows the pin assignment X1 for Thermo 90 compact kits see Fig 7 2 and Thermo 90 S heaters e with 7 Day 3 Program digital timer wiring without Deutsch connector German version see Fig 7 4 CAUTION The poles must not be looped or reversed as some components are controlled by negative polarity Glow Pin Temperature Limiter Flame Sensor Temperature Sensor Circulation Pump Combustion Air Fan Combustion Air Fan Circulation Pump Temperature Sensor 10 Flame Sensor 11 Temperature Limiter 12 Glow Pin View from rear Fig 7 1 Visual Inspection Burner Rear Wall THERMO 90 90 S 7 Circuit DIAGRAMS OONWPSC Q3SIA33 IOHLNOO 695195 712806 ON DMG 06 ONYJHL 1 SLIM SYNSOTONA LOVdWOO JILVWAHOS 1v2IN123 13 06 ONS3HI OISV83M HOLIMS 3JO NO 15 dWhg INJ 1 AVM 6 NOLO3NNOO X AVM NOLO
8. The Webasto Thermo 90 and 90 S coolant heater in combination with the vehicle s own heating system is used to heatthe cab sleeper or interior areas of vehicles defog defrost windshields preheat water cooled engines The coolant heater operates independent from the vehicle engine and is connected to the cooling system the fuel system and the electrical system of the vehicle The heater is designed around the Ferro Tec Technology evaporator burner system and operates intermittently controlled by the temperature sensor Dependent on the deviation of the current coolant temperature from the rated value of the temperature sensor combustion performance is continuously controlled within a range from 1 8 to 7 6 kW 6 100 to 26 000 Btu hr for Diesel operated heaters and within 2 0 to 7 6 kW 6 800 to 26 000 Btu hr for gasoline operated coolant heaters For an extremely high heating performance requirement preheating the maximum performance of 9 1 kW 31 000 Btu hr is available with NOTE One of the newer models shown Older models have the temperature sensor cable located on the side Heater Thermo 90 2 GENERAL DESCRIPTION diesel operated coolant heaters for up to 2 hours after heater actuation The Webasto Thermo 90 and 90 S coolant heaters basically consist of combustion air fan heat exchanger burner insert with combustion tube e Circulation pump For control and monitoring the following are
9. Torque tighten hose clamp with 1 Nm 10 Make electrical connections see 9 2 1 2 Install heater see 8 7 1 2 ON THERMO 90 90 S 9 2 4 Replacement of Temperature Sensor 9 2 4 1 Removal 1 Remove heater see 8 7 1 1 2 Disconnect electrical connections see 9 2 1 1 AWARNING Escaping hot coolant may cause burns 3 Unscrew temperature sensor 6 Fig 9 3 and remove together with O ring 5 4 Perform procedures on components after disassembly see 9 1 1 9 2 4 2 Installation 1 Apply acid free grease Vaseline to O ring 5 Fig 9 4 2 Screw temperature sensor 6 with O ring 5 into heat exchanger 4 and torque tighten to 1 5 Nm 410 3 Make electrical connections see 9 2 1 2 4 Install heater see 8 7 1 2 THERMO 90 90 S 9 REPAIR NOTE One of the newer models Thermo 90 shown Older models have the cable of the temperature limiter located on the side Heater Thermo 90 S may have the control unit located on the combustion air fan not affecting the replacement of the temperature limiter and temperature sensor Protective Cap Clamp Temperature Limiter Heat Exchanger O Ring Temperature Sensor Fig 9 3 Replacement of Temperature Limiter and Temperature Sensor 9 5 9 REPAIR 9 2 5 Replacement of Combustion Air Fan 9 2 5 1 Removal 1 Remove heater see 8 7 1 1 2 Disconnect electrical connections see 9 2 1 1 3 Remove screws 2 Fig 9 4 4
10. e Check sleeper blower operation by turning on the thermostat Allow the fan to cycle on and off to ensure proper functioning 8 1 8 SERVICING THERMO 90 90 S NOTE The manufacturer mounts the control unit of Thermo 90 S heater to the combustion air fan With Check Valve and Thermostat 1 Heat Exchanger Vehicle Heating System 2 Blower Switch Vehicle Heating System 3 Relay for Vehicle System 4 Timer 5 Fuse Box in Vehicle 6 Check Valve with Drain Hole 7 T Junction 8 Vehicle Engine 9 Heater Unit 10 Circulation Pump 11 Engine Coolant Pump 12 Radiator 13 Regulating Valve 14 Control Unit 15 Exhaust Muffler 16 Fuel Dosing Pump L jig 5 poet pa ERES EE 17 Combustion Air Intake Line p 9 TAE A Es C i 18 Thermostat SEX 557 v 777 Cable Loom Fuel Line 775 Exhaust Line Coolant Circuit Without Check Valve Fig 8 1 Examples for Heater Installation 8 2 THERMO 90 90 S 8 6 Visual Inspections and Installation Regulations 8 6 1 Connection to the Vehicle s Cooling System In thermostat circuits only thermostats opening at 65 149 F are to be used The installation of the heater should be in a location as low as possible to ensure static priming of the heater and circulation pump This applies in particular for the circulation pump which is not self priming The heater is to be connected to the cooling system acc
11. Bleed fuel supply system Bleed coolant circuit 8 SERVICING 8 7 2 Replacement of Circulation Pump NOTE The proceaure for replacement of the circulation pump is identical with the heater removed or installed Replacement is to be performed in accordance with instructions described in section 9 2 2 8 7 3 Replacement of Temperature Limiter NOTE The procedure for replacement of the temperature limiter is identical with the heater removed or installed Replacement is to be performed in accordance with instructions described in section 9 2 3 8 7 4 Replacement of Temperature Sensor NOTE The procedure for replacement of the temperature sensor is identical with the heater removed or installed Replacement is to be performed in accordance with instructions described in section 9 2 4 8 7 5 Replacement of Combustion Air Fan NOTE The procedure for replacement of the combustion air fan is identical with the heater removed or installed Replacement is to be performed in accordance with instructions described in section 9 2 5 8 8 First Operation After installation of the heater the fuel supply system and the cooling circuit must be thoroughly bled observing the vehicle manufacturer s instructions During the test run of the heater all connections are to be checked for leakage and tightness Should the heater assume an error lock out condition during operation perform troubleshooting see Sectio
12. 0 360 1 3 1 44 Q 5mA 5mA 6 FUNCTIONAL TESTS 6 3 3 Flame Sensor Resistance Test During electrical testing of the flame sensor using a digital multi meter the following readings should be obtained Cold Test Resistance at 25 C 77 F 2 6 3 40 Test current 5 mA Hot test Resistance at 800 1000 12 15 0 1472 1832 F ceramic rod red hot over a length of approx 20 mm Test current lt 5 6 3 4 Combustion Air Fan Test The motor speed check must be performed with the heater assembled and within the operating voltage range During the test check for grinding noises NOTE For the motor speed check the fan cover must be removed Prior to re installation the gasket is to be replaced ACAUTION Pay attention not to break off the locking cams otherwise replace cover and gasket Speed in control range min 1800 rpm Speed in control range max 6100 rpm 996 996 In the event speed values are out of tolerance replace combustion air fan see 9 2 5 NOTE On the Thermo 90 the function of the combustion air fan can be checked with the diagnostic computer or the components tester On the Thermo 90 S the check is performed by means of the PC heater diagnosis 6 1 THERMO 90 90 S 7 CiRCUIT DIAGRAMS T Circuit Diagrams The circuit diagrams Figs 7 3 and 7 5 show possible circuits of the Thermo 90 S heater with 7 1 General with standard switch and harness wiring using
13. 15 Volt 10 15 or 20 30 Volt Rated power consumption with circulation pump without vehicle blower Maximum Control range 90 W 37 W 83 W 37 W 83 W Permitted ambient temperature Heater operation storage Control unit operation storage Fuel dosing pump operation storage 40 110 40 130 C 40 75 40 85 40 20 40 40 40 85 C Permitted over pressure heat exchanger Maximum 2 0 bar Heat exchanger capacity 0 151 Maximum combustion air intake temperature 40 Coolant circuit minimum capacity 6 00 I Volume flow of circulation pump against 0 15 bar 1650 1 CO2 in exhaust permissible operating range 10 12 0 Vol CO2 setting values at approx 20 C and geographical height above SL 500 m 1000 m 10 6 11 3 Dimensions of heater Tolerance 3 mm Length 310 mm 355 Width 133 mm Height 220 mm Weight 4 8 kg 9 Thermo 90 S with control unit mounted on heater THERMO 90 90 S 5 TROUBLESHOOTING 5 Troubleshooting ACAUTION Troubleshooting is normally limited to the isolation of defective components 5 1 General The following defects are not included in the troubleshooting procedures Before troubleshooting This section describes troubleshooting procedures for check for and eliminate these defects the The
14. line joints are to be secured against loosening with hose clamps Connection of 2 Pipes with Hose The proper connection of fuel lines with hoses is shown in Fig 8 4 Correct Wrong Fig 8 4 Pipe Hose Connection 8 SERVICING 8 6 8 Fuel Dosing Pump The fuel dosing pump is a combined delivery dosing and shut off system and is subject to certain installation criteria see Figs 8 2 and 8 5 Model DP 30 0 90 0 90 ei za 0 b Thermo 90 905 12 Volt and 24 Volt Diesel Installation Position Horizontal Only Fig 8 5 Fuel Dosing Pump Installation Location and Attachment 8 6 3 1 Installation Location It is advantageous to mount the fuel dosing pump in a cool location as near as possible to the fuel tank The ambient temperature must never exceed 20 C 68 F for gasoline and 40 104 F for Diesel installations at any time while in operation The maximum pressure at the tapping location must be below 1 5 bar 21 75 psi Fuel dosing pump and fuel lines must not be installed in locations exposed to heat radiated by hot vehicle components A heat shield is to be provided as required 8 5 8 SERVICING THERMO 90 90 S 8 6 3 2 Installation and Attachment The fuel dosing pump is to be attached with anti vibration mounts The installation location is limited according to Fig 8 5 to ensure sufficient self bleeding capability Due to the danger
15. of corrosion the plug connection between fuel dosing pump and fuel dosing pump cable loom may only be fitted with Webasto original spare parts 8 6 4 Fuel Filter If there is the probability of contaminated fuel only the Webasto filter part number 487171 may be used The use of fuel filters not designed for Webasto heater fuel systems may cause a vapor lock or interfere with the proper delivery of fuel The fuel filter can be installed anywhere between the vertical and horizontal positions but must be installed in the direction of flow 8 6 5 Combustion Air Supply Combustion air must under no circumstances be extracted from rooms with persons The combustion air inlet must not point towards the forward direction of motion It must be located so that no clogging by contamination impact of snow or intake of splash water is possible The combustion air intake line inner diameter at least 30 mm or 1 3 16 in may have a length from 0 5 m to 5 m 18 in to 16 ft with several bends totaling no more than 360 Smallest bending radius is 45 mm 1 3 4 in The combustion air inlet must not be located above the exhaust outlet NOTE The combustion air intake line is to be routed in a downward direction If this is not possible a water drain hole 4 mm or 5 82 in dia must be provided at the lowest point If the heater is located near the fuel tank in a common installation compartment combustion air must be taken in from and
16. radiation of engine heat may cause gas bubbles to build up in the fuel lines causing malfunctions in the combustion operation When installing the heater in vehicles with fuel injection systems the fuel pumps location within or outside the fuel tank must be investigated first If the fuel pump is fitted inside the fuel tank the fuel may be tapped only from the return line ensuring that the return line is routed almost to the tank floor If this is not the case the fuel line may be lengthened In case of a fuel pump mounted externally to the tank the fuel tap can be located between the fuel tank and the fuel pump THERMO 90 90 S 8 6 2 2 Fuel lines Fuel lines may only be steel copper or plastic lines made of unhardened light and temperature stabilized PA 11 or Pa 12 e g Mecanyl RWTL according to DIN 73378 As in most cases if a permanently rising fuel line routing cannot be ensured the inner diameter must not exceed a certain value Starting from an inside diameter of 4 mm 5 32 in air or gas bubbles accumulate resulting in malfunctions should the lines be descending or having sags The diameters specified above 2 mm ensure a non accumulation of air bubbles A descending line routing from the fuel dosing pump to the heater should be avoided Loose fuel lines must be secured in order to avoid sagging The installation must ensure protection against stone impacts and undue temperatures exhaust line The fuel
17. the combustion air fan on Thermo 90 S heaters 2 11 Fuel Dosing Pump Fuel supply to the heater and its dosing is ensured externally by a fuel dosing pump When the heater is deactivated it also serves as a shut off valve The magnetic coil of the dosing pump receives the pulses from the microprocessor of the control unit THERMO 90 90 S 3 Functional Description Fig 3 1 3 1 Switch on When operating the push button Immediate Heating the Operating Indicator on the timer illuminates or by activation with the switch the Operating Indicator integrated in the switch illuminates Circulation pump glow pin and combustion air fan are put into operation 3 2 Heating Operation After approx 50 seconds combustion commences with the automatically controlled heating operation in full load for a maximum of 2 hours The vehicle s own heating blower starts to operate only after the heat carrier coolant has accumulated enough heat After reaching the pre coded rated temperature see table Control Temperatures heating performance precision control will take over in stages down to the lowest part load operation 3 3 Control Operation If the coolant temperature rises up to the control idle threshold the heater enters the control idle phase The circulation pump the vehicle s own blower and the operating indicator remain in operation during the control idle period After the coolant has cooled down to the pre c
18. the exhaust routed to the exterior The feed through openings must be splash waterproof If the heater is located in a closed installation box a vent port of at least 6 cm2 2 3 8 in2 is required If the temperature in the installation box exceeds the permitted ambient temperature of the heater see Technical Data the vent port must be enlarged 8 6 8 6 6 Exhaust Line The exhaust line inner diameter 38 mm or 1 5 in may have a length from 0 5 m to 5 m 18 in to 16 ft and be routed with several bends totaling no more than 360 Smallest bending radius is 85 mm 3 3 8 in The exhaust muffler is mandatory and to be mounted near the heater In order to ensure the angle of 90 10 an attachment is required no further than 150 mm 6 in away measured from the exhaust pipe end Exhaust exit direction nearly vertical 90 10 Fig 8 6 Exhaust Outlet Direction of Flow The exhaust pipe outlet opening must not point in the direction of motion see Fig 8 6 The exhaust pipe outlet opening must be located so as not to allow clogging by snow or mud Rigid exhaust line pipes can be made of unalloyed or alloyed steel but must have a minimum wall thickness of 1 0 mm 1 32 in Flexible exhaust pipes must be made only of alloyed steel The exhaust pipe is secured to the air heater with a clamp For further requirements consult Webasto Thermosystems THERMO 90 90 S 8 7 Removal and Installation ACAUTIO
19. 3NNOO AVM Z NOLO3NNOO ZX AVM ZL MOLO3NNOO LX AVM tY YOLOZNNOD DILSONDVIO Q AWM Z NHOLO3NNOO 2 AVM OL MOLO3NNOO AVM 8 NOLO3NNOO vV vNOlLdO 1VISOWN3HL WOON 1 dnd LNVIOOD ZN YOLOW NIV NOLLSNSWOD IN VOZ 3ShJINNIN 4 VG JSNJNIN 4 VOL 3SNJININ 13 Nid 3 LHOM MOLVOIQNI SQ AuaiLva 18 33n1vH3dW3L MOSN3S 34nivH3dW31 28 H0123130 3 v14 18 SS3NHvH 3721H3A 03395 8M0 Fig 7 2 Circuit Diagram Thermo 90 12 and 24 V Enclosure and Compact Kit with Deutsch Connector 7 2 7 CiRCUIT DIAGRAMS THERMO 90 90 S 506 OLSVSIM 3LIHM 3n 18 2 9 NMOua LINN TOXLNOS 118195 494 9000 000 SCO8 JUVNW3HOS 414 506 OWYSHL OISV83JM 5 ek 4 zd Ld H g zl RET ra ae mal ESI 25i 2 og 2 ee NISI ml at l AAS i drag 98 se 1 p MH 57 MEER Fc m 4 lt Ir ui 1 dWAd 1903 LA AVIWZ YOLOANNOD LX HOLO3NNOO ZLX AVAZI HOLOJNNOO LLX AVM 6 YOLOANNOD SX AWM YOLOANNOD DILSONDVIC AVM HOLO3NNOO AVM2 HOLO3NNOO 2X AVM ZL YOLOANNOD LX IVISOWHNSHI NOON 1 YOLOW Y4MO1E EN YOLOW NOILSNEWOD ZN N
20. 90 S 9 REPAIR 9 2 7 Replacement of Burner Head 9 2 7 2 Installation 9 2 7 1 Removal NOTE Burner head and exhaust outlet pipe can still be aligned 1 Remove heater see 8 7 1 1 during installation in vehicle 2 Remove combustion air fan see 9 2 5 1 3 Remove burner flame sensor and glow pin 1 Insert burner head 1 Fig 9 6 into heat exchanger see 9 2 5 1 3 align as necessary and secure with V clamp 2 4 Remove attachment screw of V clamp 2 Fig 9 6 2 Torque attachment screw of V clamp to 3 Nm 1096 and pull off clamp as required 5 Withdraw burner head 1 from heat exchanger 3 3 Install burner flame sensor and glow pin and remove see 9 2 6 2 6 Perform procedures on components after 4 Install combustion air fan see 9 2 5 2 disassembly see 9 1 1 5 Install heater see 8 7 1 2 NOTE Carefully inspect the gasket located at the joint between the alloy burner head and stainless steel burner tube especially at the area of the exhaust outlet Any deterioration of this gasket will require the replacement of the burner head tube assembly NOTE One of the newer models of Thermo 90 shown Older models have the cable of the temperature limiter located on the side lllustration is also applicable to the Thermo 90 S 1 Burner Head 2 V Clamp 3 Heat Exchanger Replacement of Burner Head 9 9 9 REPAIR 9 2 8 Replacement of Heat Exchanger 9 2 8 1 Removal Remove heater see 8 7 1 1
21. N It is permissible to service the heater in the installed position only if sufficient space is available for removal and disassembly of the various components of the heater Should there not be sufficient space or there exists a possibility of damage to the components of the heater during disassembly the heater must be removed from the installed position 8 7 1 Heater Removal and Installation 8 7 1 1 Removal 1 Disconnect battery terminal leads NOTE On the Thermo 90 S heater with control unit flanged to combustion air fan only connectors X12 and X13 require disconnection from control unit Remove top cover Disconnect plug of cable loom from heater Disconnect fuel inlet on heater Loosen hose clamps and disconnect coolant hoses from heater Disconnect combustion air intake and exhaust outlet tubes at heater 7 Remove three nuts and washers from heater mount 8 Remove heater o ON 9 8 7 1 2 Installation 1 Locate heater in installation position and secure with three nuts and washers 2 Reconnect coolant hoses and secure with hose clamps Torque tighten clamps to 5 Nm 3 Reconnect fuel line to heater 4 Reconnect combustion air inlet and exhaust outlet tubes at heater NOTE On the Thermo 90 S heater with control unit flanged to combustion air fan reconnect connectors X12 and X13 to control unit Connect plug of cable loom to heater Plug on top cover and arrest Reconnect battery terminal leads
22. OILYINDYID LNVIOOS LN YOLOW AVI3H bY 02 ISNA ININ 4 vs ISNA VOL ISNA bd YALINSISINVHAD 1 NOILY3H3dO d AN3liVH 3H 1VH3dW31 5 5 3HnlVuH3dW3l Fig 7 3 Circuit Diagram Thermo 90 S 12 and 24 V Enclosure and Compact Kit with Deutsch Connector 7 3 7 Circuit DIAGRAMS Thermo 90 Basic Kit Wiring German E B2 X dE LM Mt em B3 x1 THERMO 90 90 5 B Li eee X4 8B 8 4 2 08 6 4 2 Br B y E M 699999 a B O24 T 2 31 11 109 8 7 58 15 15 75 15 30 31 For gasoline heaters remove this connection Temperature coding temperature at water outiet see table page 3 2 Timer P with plus at connection 4 7 permanent operation in immediate heating without plus at connection 4 heating period 1 hour Nomenclature Remark Heater Thermo 90 Wire Colours br brown e ello Wire Gauges 3 VeRO gn green 75m 75 15m 9r grey 075 mm 1 5 2 ar orange 1 0mm 1 5 mm rt red 15mm 25mm AM black 25mm 40mm M violet 40mm 60mm We white Nomenclature Remark Motor Vehicle blower Control Unit 50 1569 Te
23. Pull combustion air fan 1 from burner head 4 and remove together with profiled packing ring 3 NOTE On heater Thermo 90 S with flanged control unit remove control unit as required 5 Perform procedures on components after disassembly see 9 1 1 Thermo 90 S Control Unit 1 Combustion Air Fan 2 Screw 2 3 Profiled Packing Ring 4 Burner Head 9 6 THERMO 90 90 S 9 2 5 2 Installation NOTE Locate packing ring 3 Fig 9 4 properly do not squeeze 1 Bring combustion air fan 1 with new profiled packing ring 3 in assembly position and secure with screws 2 2 Torque tighten screws 2 with 3 Nm 10 NOTE On heater Thermo 90 S with flanged control unit install control unit as required 3 Make electrical connections see 9 2 1 2 4 Install heater see 8 7 1 2 Fig 9 4 Replacement of Combustion Air Fan THERMO 90 90 S 9 2 6 9 2 6 1 Replacement of Burner Flame Sensor and Glow Pin Removal Remove heater see 8 7 1 1 Remove combustion air fan see 9 2 5 1 Remove screw 5 Fig 9 5 and washer 4 Remove nuts 10 and withdraw bracket Withdraw grommets 11 and 12 from slots in housing of combustion tube 3 6 Withdraw grommet 13 and burner 1 from burner 1 and remove 7 Pull flame sensor 7 and glow pin 6 out of burner 1 and remove 8 Perform burner visual inspection for assessment of condition see 9 1 1 9 Perform pro
24. S CD Switch on 2 Configuration Check 9 Preheating 40 sec cycled Fuel Dosing Pump Priming 5 7 sec 1 9 Fuel Dosing Pump Part Load 1 4 6 Flame Sensor Take over Stabilization Period Full Load 9 Vehicle Blower On optional Control Range Control Idle Flame Sensor cold 0 09 Run down completed Preheating 15 20 sec cycled 5 Fuel Dosing Pump Priming 5 7 sec 1 Fuel Dosing Pump Part Load 1 4 Flame Sensor Take over Stabilization Period Coolant Temperature down Full Load Switch off run down Flame Sensor cold 0 3 Run down completed Glow Pin Fuel Dosing Pump Combustion Air Fan Flame Sensor Operation Indicator Light Circulation Pump Vehicle Blower optional oQmmoou m THERMO 90 90 S n case of a no flame condition automatic restart is initiated 20 sec cycled preheating 90 sec safety time Possible codeable control temperatures see table below Functional Sequence Setting of Control Temperatures Thermo 90 Table Rated Temp Control Reactivation at Sensor Idle after Control Idle Minus to B6 80 C 90 C 75 C B6 not used 72 82 C 67 C Plus to B6 65 C 75 60 On the enclosure and compact kits B6 is connected to minus Setting of Control Temperatures Thermo 90 S Connection of a plus or minus signal to the control unit conn
25. S MERCEDE eee ed vs 3 Functional Description Fig 3 1 3 1 SWINGIN Sedet vios De raa d Caci Cae rdc es Seer aia on nh eda 3 2 Heating Operation 3 2 avare ados Guidone aco Fg se ao dabo Eo 3 3 Control Operation 3 4 SOWIEGEISBITE earn eo pc ent ef s 3 5 Malfunctions od san Jan eh mee B 3 5 1 Switch off upon Failure 3 5 2 Diagnosis after Switch off upon Failure Thermo 90 3 5 3 Diagnosis after Switch off upon Failure Thermo 90 5 3 5 4 Reading and Understanding the Flash Code 4 Technical Data Standard Measure 4 Technical Data Metric Measure 5 Troubleshooting 5 1 C PT Emm 5 2 General Failure Symptoms 3 8 5 3 Failure Symptoms after Switch off upon Failure 5 4 a Fault Code in Memory TABLE OF CONTENTS THERMO 90 90 S 5 4 1 Reading and Removing Error Codes Stored in Memory using the Diagnostics Kit P N 925420 5 3 5 5 Visual Inspection for Assessment of Burner Condition 5 4 5 5 1 Burner HOUSING
26. X6 2 0 rt X12 ST 2 x ST 1 ST 3 t t n 85 8 87 B ELE 1 58 asl ao x sw lt 31 es 9 1 Wire Colours Temperature coding temperature at water outlet see table 3 2 Wire Gauges ge yellow Timer P2 gn green with plus at connection 10 permanent operation in instant heating 75m 75 15m gr grey without plus at connection 10 heating period programmable 10 min to 120 min 10 75 mm 15mm or orange basic setting 120 min lomm 15mm t red 5mm 25mm Bw black 25mm 40mm v violet 40 mm 60mm ws white Nomenclature Remark Nomenclature Remark Heater Thermo 90 Thermo 90 S 58 Switch button Instant heat switch remote control Control Unit Connection 12 pole on item A1 Flame Sensor Connection 12 pole onitem P2 Temperature Sensor Connection 2 pole Temperature Limiter X6 Connection 2 pole Diagnosis Room Thermostat Xii Connection 12 pole on item A2 ST 1 Glow Plug Connection 12 pole on item A2 ST 2 Fuse 20A Flat Fuse SAE J 1284 Connection 2 pole onitem A2 ST 3 Fuse 5A Flat Fuse SAE J 1284 Dosing pump Fuse 20A Flat Fuse SAE J 1284 Symbol for Heating in Display Operation Indication in item P1 or P2 Light Symbol illumination in item P1 or P2 LED red in item P2 Illumination instant heat switch standby indication on indication Relay For vehicle blower
27. ading is used to highlight that non compliance with instructions or procedures may cause injuries or lethal accidents to personnel ACAUTION This heading is used to highlight that non compliance with instructions or procedures may cause damage to equipment NOTE This heading is used to highlight and draw specific attention to information 1 3 Additional Documentation to be Used This workshop manual contains all information and procedures necessary for the repair of heaters Thermo 90 and Thermo 90 S The use of additional documentation is normally not necessary Operating instructions installation instructions and the vehicle specific installation guides when available may be used as complementary information if necessary 1 INTRODUCTION 1 4 General Safety Regulations and Information The general safety regulations for the prevention of accidents and relevant operating safety instructions must be observed at all times The specific safety regulations applicable to this manual are highlighted in the individual chapters by Warnings Cautions and Notes 1 4 1 General Safety Notes The heater may only be installed in motor vehicles or in independent heating systems with a minimum coolant capacity of 6 litres 1 6 US Gal The heater must not be installed in the passenger compartments of vehicles Should the heater be installed in such a compartment the installation box must be sealed tight against the vehicle inte
28. at 9 at 3 connector X12 Thermo 90 S Replace control unit Check fuel level Check fuel filter Bleed fuel system Check combustion air exhaust duct for foreign matter and clean as required Clean burner or replace as necessary Check fuel level Check fuel filter Bleed fuel system Clean burner or replace as necessary Check battery load test Check electrical connections Replace flame sensor Check wiring for damage open connections or short circuit Replace flame sensor Check wiring for damage open connections or short circuit Replace temperature sensor Check wiring for damage open connections or short circuit Replace fuel metering pump Check coolant level Bleed coolant circuit Reset temperature limiter Fig 5 2 Failure Symptoms after Switch off upon Failure Part 1 of 2 THERMO 90 90 S Failure Symptom 8 Flash pulses F 08 combustion air fan Wiring Combustion air fan defective 9 Flash pulses F 09 glow pin Wiring Glow pin defective 10 Flash pulses F 10 temperature limiter Thermo 90 S only Coolant circuit Wiring 11 Flash pulses F 11 coolant circulation pump Thermo 90 S only Wiring Coolant circulation pump defective 5 TROUBLESHOOTING Check wiring for damage open connections or short circuit Replace replace combustion air fan Check wiring for damage open connections or short circuit Replace glow pin Check coolant level Bleed coolant circu
29. cedures on components after disassembly see 9 1 1 9 2 6 2 Installation 1 Locate swirl ring 2 Fig 9 5 on burner 1 2 Carefully and fully insert flame sensor 7 and glow pin 6 into burner against stops and slide grommets 11 and 12 down slots in housing of combustion tube 3 3 Position burner 1 and grommet 13 in burner head 3 9 REPAIR ACAUTION When performing the following step ensure that cables of flame sensor 7 and glow pin 6 are routed as shown in figure 4 Glow Pin Slide insulation 9 onto bracket and locate bracket 8 in assembly position NOTE Route cables of flame sensor and glow pin as shown in figure above 5 6 Secure bracket 8 using nuts 10 Torque nuts to 3 Nm 1096 Secure fuel line with screw b and washer 4 Torque screw to 3 Nm 1096 Mount combustion air fan see 9 2 4 2 Make electrical connections see 9 2 1 2 Install heater see 8 7 1 2 9 7 9 REPAIR THERMO 90 90 S Burner Swirl Ring Burner Head Washer Screw Glow Pin Flame Sensor Bracket Insulation 10 Nut 2 11 Grommet 12 Grommet 13 Grommet OONODaARWDH NOTE One of the newer models of Thermo 90 shown Older models have the cable of the temperature limiter located on the side Illustration is also applicable to the Thermo 90 S gt Fig 9 5 Replacement of Burner Flame Sensor and Glow Pin 9 8 THERMO 90
30. cle s Cooling System 8 3 8 6 2 Connection to the Vehicle s Fuel System 8 3 9 5 2 1 Fuel Tapping amer hd ee Ee Rt Ree E oe lon wae oin 8 4 9 52 2 ness a suec re dons dert tss cain hein ahy i els ena e 8 5 8 6 3 Fuel DOSING Aim RU RR UNDE ee SE aus 8 5 8 6 3 1 Installation Location lee eee eee 8 5 8 6 3 2 Installation and Attachment 8 6 8 6 4 Fuel Bitat Rees WO Rer ROTE DPA RD 8 6 8 6 5 Combustion Air Supply 8 6 8 6 6 11 aod EA RACER RC EN US 8 6 8 7 Removal and Installation cle RR 8 7 8 7 1 Heater Removal and Installation 8 7 Qd Removal du Rona re Ravers wi co ee E Rat 8 7 THERMO 90 90 S TABLE OF CONTENTS 8 7 1 2 Installation Xow ek os Ce ded RES UAR ae aes 8 7 8 7 2 Replacement of Circulation Pump 8 7 8 7 3 Replacement of Temperature Limiter 8 7 8 7 4 Replacement of Temperature 8 7 8 7 5 Replacement of Combustion Air Fan 8 7 8 8 First Operations corriera Pre IR e
31. delivery height D 3 m 9 9 8 SERVICING 8 6 2 1 Fuel Tapping Fuel tapping must be from the fuel reservoir or from a separate tank Fig 8 3 This separate fuel tapping avoids an influence on the pressure Hole Pattern SS lt gt 25 mm 1 in gt 25 mm 1 in Fig 8 3 Webasto Fuel Tank Use fuel tap only on metal fuel tanks THERMO 90 90 5 Vehicles with Gasoline Engines In combination with carburetor equipped or fuel injected gasoline engines with a return line the heater s fuel system integration must be in the return line Carburetor equipped gasoline engines without a return line must have the heater integrated in the fuel supply between the vehicle s fuel tank and fuel pump NOTE A fuel supply line can normally be identified by an installed fuel filter If an exhalation vessel is installed in the vehicle s fuel system fuel tapping must be upstream of the exhalation vessel For fuel tapping from the supply or return line only the specific Webasto fuel tap T e g Ident No 470910 for 8 mm ID may be used The fuel tap must be mounted so that the air or gas bubbles can escape towards the fuel tank Air or gas bubbles may build up in the vehicle fuel line in case of a leak in the vehicle s carburetor or fuel pump or when environmental temperatures are higher than the fuel evaporation temperature The fuel tap should not be located in the engine compartment because the
32. e equal around the entire circumference insulation 4 Fig 5 3 must be present Combustion Swirl Ring Air Bores Gap between Housing and Combustion Chamber Fig 5 5 Visual Inspection Burner Assembly 5 5 THERMO 90 90 S 6 Functional Tests 6 1 General This section describes the on vehicle and off vehicle testing of the heater to check for proper operation A WARNING The heater must not be operated not even with timer in enclosed areas like garages or workshops not equipped with an exhaust venting facility 6 2 Adjustments 6 2 1 Adjustment of the CO2 Content A change of the combustion air volume set by the manufacturer may be performed by rotating the air set Screw Setting Procedure Clockwise rotation value decreases prior to measurement heater must have been in operation for at least 5 min Coarse setting Rotate air set screw clockwise fully in and then back one turn 6 3 Components Testing 6 3 1 Temperature Sensor Resistance Check During electrical testing of the temperature sensor using a digital multi meter the following readings should be obtained Resistance at 25 C 77 F Test current 990 1010 Q lt 1mA 6 3 2 Glow Pin Resistance Test During electrical testing of the glow pin using a digital multi meter the following readings should be obtained Glow pin Resistance at 25 C 77 F Test current 12 Volt red 24 Volt green 0 324
33. ector X12 contact 7 will enable different threshold values Table Rated Temp Control Reactivation at Sensor Idle after Control Idle Plus 72 82 67 C Minus 80 90 75 C On the enclosure and compact kits connector X12 contact 7 is connected to minus NOTE In the case of both heater models the selected control idle temperature of the heater should be below the opening temperature of the engine thermostat 90 90 5 3 5 Malfunctions 3 5 1 Switch off upon Failure In case of a no flame condition fuel is delivered for a maximum of 180 seconds In the event of a flame out during operation fuel is delivered for a maximum of 90 seconds Should an overheat condition exist after response of the temperature limiter no fuel will be delivered After switch off by low voltage protection for more than 20 seconds there will be no fuel delivery Thermo 90 Thermo 90 S 12 Volt 10 5 0 5 V 10 5 0 5 V 24 Volt 21 1V 21 1V After the correction of the fault there will be an error lock out Reset by switch off and reactivation of the heater In case of overheating the temperature limiter has to be reset after the unit has cooled down ACAUTION To avoid damage to the component do not attempt to reset the temperature limiter by force while hot 3 5 2 Diagnosis after Switch off upon Failure Thermo 90 When operated with switch or digi
34. ell as black or other discolorations of the evaporator do not cause a burner failure and are meaningless Coke deposits on the evaporator surface except for the pilot flame exit bore are normal and must not be removed When the load changes from full load to part load and vice versa the burner normally is self cleaning Pilot Flame Exit Bore Metal Evaporator Fuel Pilot Flame Exit Bore CE ti Metal Evaporator Diesel Fig 5 4 Visual Inspection Pilot Flame Exit Bore 5 TROUBLESHOOTING 5 5 3 Combustion Chamber combustion chamber Fig 5 5 should not be damaged e g dented A combustion chamber with dents may cause insufficient combustion or coking of the heater Remedy Replace burner assembly The air bores Fig 5 5 in the combustion chamber must not be coked Coked air bores may cause a no start or insufficient combustion Remedy Removal of coke deposits by careful scraping 5 5 4 Burner Assembly The cables of the glow pin and flame sensor must be routed as shown in Fig 5 3 screwed connection of the housing and combustion chamber must be secure Fig 5 5 Housing and combustion chamber Fig 5 5 must be connected securely without any play check by slight movement of fuel pipe The O ring must have a tight fit around the fuel chamber upper edge Fig 5 3 and must seal completely e The gap between housing edge and combustion chamber upper edge Fig 5 5 must b
35. er in enclosed areas like garages or workshops not equipped with an exhaust venting facility 8 SERVICING 8 5 Annual Maintenance Before or after each heating season the following maintenance procedures should be performed to maintain the heater s functional reliability Heater and Enclosure Clean heater exterior and interior of enclosure of any accumulated debris and dust with compressed air or water Do not force water into electrical connections or into heater Electrical System e Examine electrical connections for corrosion at connections and for security Examine battery condition and clean terminals Load test batteries and replace as necessary Combustion Air and Exhaust System e Check exhaust and combustion air tubes for damage and for foreign matter and contamination Repair or replace damaged items as necessary Fuel System Replace fuel filter 487171 if equipped Examine fuel lines and fuel filter for leakage and damage Repair or replace damaged items as necessary Coolant System Examine coolant circuit and circulation pump for leakage and damage Examine hoses for abrasions and cracks e Check coolant level and anti freeze strength Refer to vehicle manufacturer s recommendations pertaining to coolant system maintenance Operational Test e Operate the Webasto heater for 15 minutes or more e Check coolant and fuel connections for leakage Re tighten clamps as necessary
36. he combustion air fan not affecting the replacement of the circulation pump Gasket Circulation Pump Clamp Screw 2 Fig 9 2 Replacement of Circulation Pump 9 3 9 REPAIR 9 2 3 Replacement of Temperature Limiter 9 2 3 1 Removal NOTE Perform the following procedure only when the temperature limiter needs replacement A functional check has to be performed when the temperature limiter is installed 1 Remove heater see 8 7 1 1 2 Disconnect electrical connections see 9 2 1 1 3 Remove clamp 2 Fig 9 3 and withdraw protective cap 1 4 Using screw driver lever off retaining clip and remove temperature limiter 3 5 Perform procedures on components after disassembly see 9 1 1 NOTE Whenever the temperature limiter is removed it must be renewed 9 2 3 2 Installation ACAUTION Wrong installation will cause melting of the heat exchanger 1 Insert the temperature limiter 3 Fig 9 3 into the heat exchanger 4 and press down retaining clip NOTE Make sure the retaining clip is heard to click fully in place Only then will the temperature limiter be in the proper installation position If clip does not audibly engage e clean seat of the temperature limiter on the heat exchanger e clean groove on heat exchanger e insure that the locking cams are present on both sides of the spring Renew temperature limiter if necessary Fit protective cap 1 and secure with clamp 2
37. it Reset temperature limiter Check wiring for damage open connections or short circuit Check wiring for damage open connections or short circuit Replace coolant circulation pump Fig 5 2 Failure Symptoms after Switch off upon Failure Part 2 of 2 5 4 Storing a Fault Code in Memory Once the Thermo 90 S completes the after run period cool down initiated by a failure event the current flash code will be downloaded stored in memory The Thermo 90 S can store up to four error codes Once the memory is full any additional error code will replace the earliest code stored thereby continually updating the error codes stored in memory with the four most recent malfunctions 5 4 1 Reading and Removing Error Codes Stored in Memory using the PC Diagnostics Kit P N 92542C It is possible to read and remove reset stored error codes from the Thermo 90 and Thermo 90 S control unit memory This is achieved through the use of a diagnostic interface kit connected between the heater and an IBM compatible computer having the necessary software installed The PC Diagnostic Interface Kit comes complete with interface module and cables software and instructions for use Order PC Diagnostics Kit under part number 92542C Several interface connection adapters are available for use with various heater models For this reason interface connection adapters are not included in the PC Diagnostics Kit Order the appropriate interface co
38. located inside the heater unit control unit external sensor e glow pin e temperature sensor temperature limiter On the Thermo 90 S heater the control unit is flanged to the combustion air fan It is possible to remote mount the control unit using an optional mounting bracket 4 Combustion Air Fan Fuel Connection Temperature Sensor Temperature Limiter Heat Exchanger Inlet Coolant Circulation Pump Outlet Coolant Outlet Exhaust Inlet Combustion Air 2 1 2 GENERAL DESCRIPTION _ Heater Thermo 90 S 2 1 Combustion Air Fan 2 2 Heat Exchanger The combustion air fan delivers the air required for combustion from the combustion air inlet to the burner insert combustion to the coolant circuit Temperature Limiter Temperature Sensor THERMO 90 90 S Combustion Air Fan Fuel Connection Temperature Sensor Temperature Limiter Heat Exchanger Inlet Coolant Circulation Pump Outlet Coolant Outlet Exhaust Inlet Combustion Air Control unit may also be located remotely in the vehicle The heat exchanger transfers the heat provided by THERMO 90 90 S 2 3 Temperature Sensor The temperature sensor senses the coolant temperature in the heat exchanger of the heater unit as electrical resistance This signal is fed to the control unit for processing 2 4 Temperature Limiter The overheat protecti
39. n 5 8 7 THERMO 90 90 S 9 Repair 9 1 General This section describes the repairs that may be performed on the heater Thermo 90 Thermo 90 S when removed Any further disassembly will void the warranty For re assembly only Webasto authorized spare parts kits are to be used 9 1 1 Work on Components after Disassembly ACAUTION All gaskets located between disassembled components must always be replaced and discarded 9 REPAIR 9 1 1 1 Cleaning All disassembled components must be cleaned 9 1 1 2 Visual Inspection Examine all components for damages cracks deformation wear etc and replace as necessary Examine connectors and wiring for corrosion loose contacts wrong crimping etc and repair as necessary e Check terminals for corrosion and contacts for security Repair as necessary 9 1 9 REPAIR 9 2 Disassembly and Assembly 9 2 1 Electrical Connections Fig 9 1 9 2 1 1 Disconnecting Electrical Connections Connection X1 NOTE All electrical connections are joined in the connector Prior to removal of a component the relevant electrical connections first have to be disconnected On the Thermo 90 S heater with flanged combustion air fan connector X1 on heater and connection X12 on control unit must be disconnected and reconnected after making electrical connections Fig 9 1 Removal Tool DT RT1 THERMO 90 90 S 1 Remove top cover from heater Using removal to
40. nnector for the heater model s you will likely be working with For the Thermo 90 order adapter 83661A For the Thermo 90 S order adapter 92556A In addition to working with stored fault codes the PC Diagnostics Kit allows you to do several other functions such as reading values while the heater is in operation or testing individual components Printing out of fault codes is also available user supplied printer required For further capabilities and instructions for using the PC Diagnostics Kit see the instruction manual included with the kit 5 TROUBLESHOOTING 5 5 Visual Inspection for Assessment of Burner Condition Burner and evaporator have specific features indicating their need for replacement or their serviceable condition The following describes the criteria for a correct inspection THERMO 90 90 5 5 5 1 Burner Housing The starting air bore Fig 5 3 must not be clogged otherwise there will be no start Remedy Carefully remove any contamination with a wire of 1 5 mm diameter Remove glow pin first 1 Fuel Inlet Pipe 2 O ring 3 Flame Sensor 4 Insulation 5 Glow Pin 6 Housing 7 Screw 8 Bracket 9 Starting Air Bore Fig 5 3 Visual Inspection Burner Rear Wall 5 4 TuERMO 90 90 S 5 5 2 Rear Wall with Metal Evaporator The pilot flame exit bore Fig 5 4 must not be clogged otherwise there will be no start Remedy Replace burner assembly Cracks delaminations as w
41. oded reactivation temperature the heater resumes operation Diesel Operated Coolant heaters If the coolant heater s coolant temperature is above the rated temperature but has not yet reached the threshold for control idle with the temperature dropping within 10 minutes back to rated temperature after reaching it for the first time the coolant heater reverts to the 9 1 kW 81 000 Btu hr heating stage Should the rated temperature be obtained after 10 minutes there will be an automatic reactivation to a maximum performance output of 7 6 kW 26 000 Btu hr Gasoline Operated Coolant Heaters The maximum heating performance of gasoline operated coolant heaters is always 7 6 kW 26 000 Btu hr 3 FUNCTIONAL DESCRIPTION 3 4 Switch off When switching the heater off the operation indicator on the timer switch extinguishes Combustion ends and the run down cycle is initiated The circulation pump and combustion air fan however continue operation to cool down the heater run down and are automatically deactivated after about 90 seconds A reactivation of the heater during run down is permitted Room temperature control by means of the vehicle s own heating blower may be provided in addition to employing a room thermostat 3 1 3 FUNCTIONAL DESCRIPTION 62 8 9 49 7 7 02 02 Safety Time Fig 3 1 Functional Sequence for Thermo 90 90
42. ol hook end withdraw lock wedge from connector 3 Using removal tool screw driver end press down relevant locking tab and while keeping tab depressed withdraw cables from connector 9 2 1 2 Making Electrical Connections 1 Slide cable into relevant contact pocket until locked Using removal tool screw driver end insert lock wedge in connector and press in until locked 3 Fittop cover NOTE One of the newer models Thermo 90 shown Older models have the cable of the temperature limiter located on the side Heater Thermo 90 S may have the control unit located on the combustion air fan Lock Wedge Locking Tab 12 Total Electrical Connections THERMO 90 90 S 9 REPAIR 9 2 2 Replacement of Circulation Pump 9 2 2 2 Installation 9 2 2 4 Removal 1 Apply acid free grease Vaseline to gasket 1 Fig 9 2 1 Remove heater see 8 7 1 1 2 Bring circulation pump 2 in assembly position and 2 Disconnect electrical connections see 9 2 1 1 secure using clamp 3 and screws 4 3 Remove screws 4 Fig 9 2 3 Torque screws 4 to 3 Nm 10 4 Remove clamp 3 and circulation pump 2 4 Make electrical connections see 9 2 1 2 5 Perform procedures on components after 5 Install heater see 8 7 1 2 disassembly see 9 1 1 NOTE One of the newer models Thermo 90 shown Older models have the cable of the temperature limiter located on the side Heater Thermo 90 S may have the control unit located on t
43. ompartment In these type of vehicles the fuel tanks must be located such that they do not pose a direct hazard to the exits in the event of a fire Fuel supply must not be by means of gravity or pressurization of the fuel tank e Installation instructions for Webasto fuel tanks for the fuel supply of coolant heaters in vehicles In busses the installation is not permitted in the passenger or driver s compartment fuel filler neck must not be located in the passengers or driver s compartment of any vehicle Fuel containers for gasoline fuel must not be located immediately behind the front paneling of the vehicle They must be separate from the engine so that even in the case of accident the inflammation of fuel is unlikely to be expected THERMO 90 90 S This does not apply for towing vehicles with an open cockpit All fuel containers offered in the Webasto Accessories Catalog are suitable for a maximum operating pressure of 0 15 bar over pressure All fuel containers offered in the Webasto Accessories Catalog are subjected during manufacture to individual pressure testing with at least 0 3 bar over pressure The fuel containers must either be equipped with a vent cap or be ventilated in another way ventilation line Only filler caps in accordance with DIN 73400 may be used The operational state of the heater i e an indication on or off must be clearly visible THERMO 90 90 S 2 General Description
44. on bimetal protects the heater unit from excessive operating temperatures The overheat protection responds at a coolant temperature higher than 105 C to switch off the heater 2 5 Burner Insert Within the burner insert fuel is distributed in the combustion tube across the burner cross section 2 6 Glow Pin The glow pin ignites the fuel air mixture at the start of heater operation The glow pin is acting as an electrical resistor and is located in the burner insert opposite the flame source Burner Insert Glow Pin Flame Sensor 2 7 Flame Sensor The flame sensor is a low Ohm PTC resistor changing its resistance dependent on its heating by the flame The signals are routed to the control unit for processing The flame sensor monitors the flame operating condition over the complete duration of heater operation 2 GENERAL DESCRIPTION 2 8 Combustion Tube Inside the combustion tube the combustion of the fuel air mixture takes place heating up the heat exchanger 2 9 Circulation Pump The circulation pump provides for circulation of the coolant in the vehicle and heater circuits The control unit switches the pump on for operation throughout the entire time of heater operation also in control idle 2 10 Control Unit The control unit is the central controlling device for functional sequencing and monitoring of the combustion operation It is mounted to the heat exchanger on Thermo 90 heaters and flanged to
45. ontrol switch and timer are either of the 12V or 24V type The components temperature limiter temperature sensor and flame sensor are identical in the 12V and 24V units Thermo 90 90 S Gasoline BW 80 Thermo 90 90 S Diesel DW 80 Mark of conformity S231 232 Heater type Coolant heater with Ferro Tec Technology Heat output Maximum Control range 6 800 26 000 Btu hr 31 000 Btu hr 6 100 26 000 Btu hr Type of fuel Gasoline Diesel 1 2 and Arctic Fuel consumption US gallon Maximum Control range 0 06 0 26 gal hr 0 28 gal hr 0 05 0 24 gal hr Rated voltage 12 Volt 12 or 24 Volt Operating voltage range 10 15 Volt 10 15 or 20 30 Volt Rated power consumption with circulation pump without vehicle blower Maximum Control range 37 83W 90 W 37 83W Permitted ambient temperature Heater operation storage operation storage operation storage Control unit Fuel dosing pump 40 68 F 40 40 230 F 266 F 40 167 F 40 185 F 40 104 F 40 185 F Permitted over pressure heat exchanger Maximum 29 psi Heat exchanger capacity 0 04 US gal Maximum combustion air intake temperature 4104 F Coolant circuit minimum capacity 1 6 US gal Volume flow of circulation pump against 2 0 psi 7 25 US gal min
46. ording to Fig 8 1 The amount of coolant in the cooling system must be at least 6 litres 1 6 US gal The coolant hoses used must meet the minimum requirements of DIN 73411 The hoses must be routed without kinking and for proper priming where possible in an upwards direction Hose connections must be secured with hose clamps to prevent slippage NOTE Hose clamps must be torqued to 1 5 Nm clamps previously in use or to 5 0 Nm new wide clamps New Prior to first operation of the heater or after replacement of the coolant bleed the cooling circuit Previous Heater and lines have to be installed so that a static priming is guaranteed Insufficient priming during heating operation may cause failure due to overheating Proper priming is indicated by a circulation pump almost noiseless in operation Insufficient priming during heating operation may cause the resettable temperature limiter to trip 8 SERVICING 8 6 2 Connection to the Vehicle s Fuel System Fuel is tapped from the fuel reservoir of the vehicle or from a separate fuel container Fuel lines must be of the type as described in section 8 6 2 2 of this manual The fuel system limitations are illustrated in Fig 8 2 Webasto Thermo 90 S Fig 8 2 Fuel Supply Maximum suction height A 1 m 3 3 Maximum suction length A B 2 m 6 6 Maximum delivery length D 6 m 19 6 Maximum
47. rior There must be sufficient ventilation of the installation box from the exterior in order not to exceed a maximum temperature of 60 140 F in the installation box Excessive temperatures may cause malfunctions A WARNING Due to the danger of poisoning and suffocation the heater must not be operated in enclosed areas such as garages or workshops without an exhaust venting system not even if the start up is activated by the timer or remote start device At filling stations and fuel depots the heater must be switched off as there is a potential danger of explosions Where flammable fumes or dust may build up e g in the vicinity of fuel coal wood cereal grain deposits or similar situations the heater must be switched off to prevent explosions In the vicinity of the coolant heater a temperature of 85 185 F must not be exceeded under any circumstances e g during body paint work A violation of this temperature limit may cause permanent damage to the electronics When checking the coolant level proceed in accordance with the vehicle manufacturer s instructions The coolant in the heating circuit of the heater must contain a minimum of 1096 of a quality brand glycol based anti freeze 1 1 1 INTRODUCTION Ignoring the installation instructions and its procedures will void the warranty granted by Webasto The same applies for repairs preformed by unskilled unauthorized personnel and repairs withou
48. rmo 90 and Thermo 90 S coolant heaters fuel supply plugged fuel filter or no fuel ACAUTION corrosion on battery terminals Troubleshooting requires profound knowledge about blown fuses structure and theory of operation of heater components corrosion on electrical wiring and fuses and may only be performed by skilled personnel corrosion on connectors loose contact on connectors In cases of doubt refer to Sections 2 or 3 for functional wrong crimping on connectors interrelations shut down initiated by temperature limiter After any correction of a failure a functional test has to be performed in the vehicle before switching the heater off and on again 5 2 General Failure Symptoms The following table Fig 5 1 lists possible general failure symptoms Heater switches No combustion after start or Control unit goes into error lock out off automatically repeat start Switch heater off and on again Flame extinguishes during operation If a no heating condition persists contact your Webasto service agent Heater overheats due to lack loss of Replenish coolant coolant After cool down of unit push button of temperature limiter before reactivation or replace temperature limiter Low voltage condition for more than Check fuses connections and charge 20 seconds state of battery Switch off caused by temperature After cool down of unit push button limiter of temperature limiter before reactivation or replace temperat
49. sea bon SM D E DE Rd SS 5 4 5 5 2 Rear Wall with Metal Evaporator 5 5 5 5 3 Combustion Chamber eee rns 5 5 5 5 4 BurrerASSembly eR A ade RUNDE ARE RIEN ISPs 5 5 Functional Tests 6 1 GONG ali 15 iste bs Ss Oei A Ru ere SA NE dos 6 1 6 2 Adjustments ee Re At a EROS cedet o PO OE DC Rd 6 1 6 2 1 Adjustment of the Content 6 1 6 3 Components Testing 6 1 6 3 1 Temperature Sensor Resistance Check 6 1 6 3 2 Glow Pin Resistance 6 1 6 3 3 Flame Sensor Resistance Test 6 1 6 3 4 Combustion Air Fan Test ee 6 1 Circuit Diagrams 7 1 Getletali s he teme Aq oe Be UMS erede E LS EE 7 1 Servicing 8 1 General 5 2 she else an ey sity Lusto fr dae bene 8 1 8 2 Work on the Healer 2 im ene E eme E RU RUD EUR hoe a kgs 8 1 8 3 Work on the Vehicle A eie VE ES EEUU AD PEE 8 1 8 4 Heater Test RUM IIIA atm NT at RS tear 8 1 8 5 Annual Maintenance 2 APACHE ee co ap ERE NE 8 1 8 6 Visual Inspections and Installation Regulations 8 3 8 6 1 Connection to the Vehi
50. st Unit For diagnosis Flame Sensor Timer For pre timed operation Temperature Sensor Resistor Resistor for H4 Temperature Limiter Switch for Circulation Pump For separate switch on Room Thermostat Switch Battery switch in plus Glow Plug Switch Battery switch in minus Fuse 20A Flat Fuse SAE J 1284 Transistor in item A2 Fuse 5A Flat Fuse SAE J 1284 Transistor in item A2 Fuse 20A Flat Fuse SAE J 1284 Transistor in item A2 Symbol for Heating in Display Operation Indication in item Connection 12 pole on item 1 Light Symbol illumination in item P Connection 8 pole on item LED max 20 mA Flame indication Connection 2 pole Relay in item A2 Master relay Dosing pump Relay in item A2 For circulation pump Relay For vehicle blower Relay Only required for battery switch in minus Motor Combustion air fan 7 4 Motor Circulation pump Fig 7 4 Circuit Diagram Thermo 90 12 and 24 V German Version with 7 Day 3 Program digital timer 90 90 5 7 CiRCUIT DIAGRAMS Thermo 90 S Basic Kit Wiring German H 1211109 8 7 X B 15 30 30 ANE
51. t using genuine Webasto spare parts This will void the coolant heaters Official Marks of Conformity Extracting combustion air from the vehicle interior is not permissible under any circumstance The exhaust line outlet is to be positioned below the vehicle floor to the nearest possible location of the vehicle s or cockpit side or rear end Exhaust pipes must be routed so that exhaust fumes will not penetrate into the vehicle s interior The function of any parts vital for vehicle operation must not be impaired Condensation accumulation in the exhaust line must be directly drained A condensation drain hole may be provided as required Electrical lines switch gear and control gear of the heater must be located in the vehicle so that their proper function cannot be impaired under normal operating conditions For the routing of fuel lines and the installation of additional fuel tanks the following important regulations must be adhered to Fuel lines are to be installed in such a way that they remain unaffected by torsional stresses created by vehicle and engine movement They must be protected against mechanical damage Fuel carrying parts are to be protected against excessive heat and are to be installed so that any dripping or evaporating fuel can neither accumulate nor be ignited by hot components or electrical equipment n busses fuel lines and fuel tanks must not be located in the passenger area or in the driver s c
52. tal timer the type of error lock out condition is indicated by an operation indicator light flash code while the heater is in run down After five short signals the following long flash pulses are counted 1x No start after 2 start attempts 2x Flame out during operation repeated gt 5 3x Voltage too low 4x Premature flame detection 5x Flame sensor open or short circuit 6x Temperature sensor open or short circuit 7x Fuel Dosing pump open or short circuit or Temperature limiter tripped overheating 8x Fan motor open or short circuit or wrong speed of fan motor 9x Glow pin open or short circuit 3 FUNCTIONAL DESCRIPTION 3 5 3 Diagnosis after Switch off upon Failure Thermo 90 S When equipped with a standard timer model 1531 an error code will be indicated on the timer display F 01 Nostart after 2 start attempts F 02 Flame out during operation repeated gt 5 F 03 Voltage too low or too high F 04 Premature flame detection F 05 Flame sensor open or short circuit F 06 Temperature sensor open or short circuit F 07 Fuel Dosing pump open or short circuit F 08 Fan motor open or short circuit or wrong speed of fan motor F 09 Glow pin open or short circuit F 10 Overheating F 11 Circulation pump open or short circuit When operated with a switch the type of error lock out condition is indicated by an operation indicator light flash code while the heater is in run down After five short signals the follo
53. ure limiter Fig 5 1 General Failure Symptoms NOTE In many cases the probable cause of failure may be the burner Perform a visual inspection according to 5 4 5 1 5 TROUBLESHOOTING 5 3 Failure Symptoms after Switch off upon Failure NOTE THERMO 90 90 5 The heater Thermo 90 S with standard timer outputs errors to the timer display for indication see 3 6 3 The following table may also be used as representative reference When operated with a switch the type of failure is indicated by a flash code of the operation indicator light during heater run down After five short signals the long flash pulses are counted Failure Symptom No function 1 Flash pulse F 01 no start 2 Flash pulses F 02 flame out during operation 3 Flash pulses F 03 low voltage 4 Flashes F 04 flame sensor continuously hot 5 Flash pulses F 05 flame sensor 6 Flash pulses F 06 temperature sensor 7 Flash pulses F 07 fuel metering pump temperature limiter Electrical wiring fuses Control unit defective Fuel system Combustion air exhaust duct Burner Fuel supply Burner Electrical power supply Flame sensor defective Wiring Flame sensor defective Wiring Temperature sensor defective Wiring Fuel metering pump defective Coolant circuit Thermo 90 only Check fuses Check battery connections at A5 at from A1 Thermo 90 at 12
54. wing long flash pulses are counted 1x No start after 2 start attempts 2x Flame out during operation repeated gt 5 3x Voltage too low or too high 4x Premature flame detection 5x Flame sensor open or short circuit 6x Temperature sensor open or short circuit 7x Fuel Dosing pump open or short circuit 8x Fan motor open or short circuit or wrong speed of fan motor 9x Glow pin open or short circuit 10x Overheating 11x Circulation pump open or short circuit 3 5 4 Reading and Understanding the Flash Code The five short flashes are only an indication that an error code has been registered and not to be counted Count only the long flash pulses following the five short flashes to obtain the correct code Example x 1 Flash Error code 7x would appear as this XXXXX X X X Xs Xs X X The sequence will repeat until the heater completes the run down cycle and switches off after which the error code will be stored in the control unit memory See section 5 Troubleshooting for further information 3 3 THERMO 90 90 S 4 Technical Data Standard Measure As long as no threshold values are given the following technical data is understood to include tolerances of 10 usual for heaters at an ambient temperature of 68 F and at nominal voltage and conditions Coolant Heater Type Operation 4 TECHNICAL DATA Electrical Components Control unit combustion air fan motor and fuel dosing pump glow pin c
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