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Webasto Thermo 90 Workshop Manual

Summary of Thermo 90

  • Page 1

    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 www.Webasto.Com rev. 03/2000 907400 thermo 90 thermo 90 s workshop manual coolant ...

  • Page 2: 90 / 90 S

    T able of c ontents i table of contents 1. Introduction 1.1 scope and purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1 1.2 meaning of warnings, cautions and notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-...

  • Page 3: 90 / 90 S

    T able of c ontents t hermo 90 / 90 s ii 5.4.1 reading and removing error codes stored in memory using the pc diagnostics kit p.N. 92542c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3 5.5 visual inspection for assessment of burner condition . . . . . . . . . . . . . . . ....

  • Page 4: 90 / 90 S

    T hermo 90 / 90 s t able of c ontents iii 8.7.1.2 installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7 8.7.2 replacement of circulation pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8-7 8.7.3 replacement o...

  • Page 5: 90 / 90 S

    T hermo 90 / 90 s 1 i ntroduction 1-1 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 gr...

  • Page 6: 90 / 90 S

    1 i ntroduction t hermo 90 / 90 s 1-2 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 without using genuine webasto spare parts. This will void the coolant hea...

  • Page 7: 90 / 90 S

    T hermo 90 / 90 s 2 g eneral d escription 2-1 2. General description the webasto thermo 90 and 90 s coolant heater, in combination with the vehicle’s own heating system, is used to: • heat the cab, sleeper or interior areas of vehicles • defog/defrost windshields • preheat water cooled engines the c...

  • Page 8: 90 / 90 S

    2 g eneral d escription t hermo 90 / 90 s 2-2 1 combustion air fan 2 fuel connection 3 temperature sensor 4 temperature limiter 5 heat exchanger 6 inlet, coolant 7 circulation pump 8 outlet, coolant 9 outlet, exhaust 10 inlet, combustion air 11 control unit (may also be located remotely in the vehic...

  • Page 9: 90 / 90 S

    T hermo 90 / 90 s 2 g eneral d escription 2-3 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 protection (bimeta...

  • Page 10: 90 / 90 S

    T hermo 90 / 90 s 3 f unctional d escription 3-1 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....

  • Page 11: 90 / 90 S

    Functional sequence for thermo 90/90 s 1 switch-on 2 configuration check 3 preheating 40 sec. (cycled) 4 fuel dosing pump priming 5 - 7 sec. (1) 5 fuel dosing pump / part load (1/4) 6 flame sensor take-over 7 stabilization period 8 full load 9 vehicle blower ‘on’ (optional) 10 control range 11 contr...

  • Page 12: 90 / 90 S

    T hermo 90 / 90 s 3 f unctional d escription 3-3 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 e...

  • Page 13: 90 / 90 S

    T hermo 90 / 90 s 4 t echnical d ata 4-1 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. Electrical com...

  • Page 14: 90 / 90 S

    4 t echnical d ata t hermo 90 / 90 s 4-2 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 °c and at nominal voltage and conditions. Electrical compo...

  • Page 15: 90 / 90 S

    T hermo 90 / 90 s 5 t roubleshooting 5-1 5. Troubleshooting 5.1 general this section describes troubleshooting procedures for the thermo 90 and thermo 90 s coolant heaters. Caution troubleshooting requires profound knowledge about structure and theory of operation of heater components and may only b...

  • Page 16: 90 / 90 S

    5 t roubleshooting t hermo 90 / 90 s 5-2 5.3 failure symptoms after switch-off upon failure note: 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. The heat...

  • Page 17: 90 / 90 S

    T hermo 90 / 90 s 5 t roubleshooting 5-3 failure symptom probable cause remedy 8 flash pulses (f 08) wiring check wiring for damage, open (combustion air fan) connections or short circuit combustion air fan defective replace replace combustion air fan 9 flash pulses (f 09) wiring check wiring for da...

  • Page 18: 90 / 90 S

    5 t roubleshooting t hermo 90 / 90 s 5-4 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. 5.5.1 burner housing • t...

  • Page 19: 90 / 90 S

    T hermo 90 / 90 s 5 t roubleshooting 5-5 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 well as black or other discolorations of the evaporator do not cause...

  • Page 20: 90 / 90 S

    T hermo 90 / 90 s 6 f unctional t ests 6-1 6. Functional tests 6.1 general this section describes the on-vehicle and off-vehicle testing of the heater to check for proper operation. Warning the heater must not be operated, not even with timer, in enclosed areas like garages or workshops not equipped...

  • Page 21: 90 / 90 S

    T hermo 90 / 90 s 7 c ircuit d iagrams 7-1 7. Circuit diagrams 7.1 general the circuit diagrams (fig. 7-2 and 7-4) show possible circuits of the thermo 90 heater with: • with standard switch and harness wiring using deutsch connector and blower interlock wiring with deutsch connector – north america...

  • Page 22: 90 / 90 S

    7 c ircuit d iagrams t hermo 90 / 90 s 7-2 fig. 7-2 circuit diagram – thermo 90, 12 and 24 v enclosure and compact kit with deutsch connector.

  • Page 23: 90 / 90 S

    T hermo 90 / 90 s 7 c ircuit d iagrams 7-3 fig. 7-3 circuit diagram – thermo 90 s, 12 and 24 v enclosure and compact kit with deutsch connector.

  • Page 24: 90 / 90 S

    7 c ircuit d iagrams t hermo 90 / 90 s 7-4 fig. 7-4 circuit diagram – thermo 90, 12 and 24 v german version with 7-day 3-program digital timer thermo 90 basic kit wiring (german).

  • Page 25: 90 / 90 S

    T hermo 90 / 90 s 7 c ircuit d iagrams 7-5 fig. 7-4 circuit diagram – thermo 90 s, 12 and 24 v german version with 7-day 3-program digital timer thermo 90 s basic kit wiring (german).

  • Page 26: 90 / 90 S

    T hermo 90 / 90 s 8 s ervicing 8-1 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 o...

  • Page 27: 90 / 90 S

    8 s ervicing t hermo 90 / 90 s 8-2 note: the manufacturer mounts the control unit of thermo 90 s heater to the combustion air fan. 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...

  • Page 28: 90 / 90 S

    T hermo 90 / 90 s 8 s ervicing 8-3 8.6 visual inspections and installation regulations 8.6.1 connection to the vehicle's cooling system in thermostat circuits only thermostats opening at the installation of the heater should be in a location as low as possible to ensure static priming of the heater ...

  • Page 29: 90 / 90 S

    8 s ervicing t hermo 90 / 90 s 8-4 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. Vehicles with gasoline engines in combination with carburetor equipped or fuel injected gasoline en...

  • Page 30: 90 / 90 S

    T hermo 90 / 90 s 8 s ervicing 8-5 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, ...

  • Page 31: 90 / 90 S

    8 s ervicing t hermo 90 / 90 s 8-6 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 of corrosion, the plug connection betw...

  • Page 32: 90 / 90 S

    T hermo 90 / 90 s 8 s ervicing 8-7 8.7 removal and installation caution 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 ...

  • Page 33: 90 / 90 S

    T hermo 90 / 90 s 9 r epair 9-1 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 comp...

  • Page 34: 90 / 90 S

    9 r epair t hermo 90 / 90 s 9-2 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 h...

  • Page 35: 90 / 90 S

    T hermo 90 / 90 s 9 r epair 9-3 9.2.2 replacement of circulation pump 9.2.2.1 removal 1. Remove heater (see 8.7.1.1). 2. Disconnect electrical connections (see 9.2.1.1). 3. Remove screws (4, fig. 9-2). 4. Remove clamp (3) and circulation pump (2). 5. Perform procedures on components after disassembl...

  • Page 36: 90 / 90 S

    9 r epair t hermo 90 / 90 s 9-4 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. Dis...

  • Page 37: 90 / 90 S

    T hermo 90 / 90 s 9 r epair 9-5 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 tempe...

  • Page 38: 90 / 90 S

    9 r epair t hermo 90 / 90 s 9-6 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. Pull combustion air fan (1) from burner head (4) and remove together with profiled packing ri...

  • Page 39: 90 / 90 S

    T hermo 90 / 90 s 9 r epair 9-7 9.2.6 replacement of burner, flame sensor and glow pin 9.2.6.1 removal 1. Remove heater (see 8.7.1.1). 2. Remove combustion air fan (see 9.2.5.1). 3. Remove screw (5, fig. 9-5) and washer (4). 4. Remove nuts (10) and withdraw bracket. 5. Withdraw grommets (11 and 12) ...

  • Page 40: 90 / 90 S

    9 r epair t hermo 90 / 90 s 9-8 fig. 9-5 replacement of burner, flame sensor, and glow pin 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..

  • Page 41: 90 / 90 S

    T hermo 90 / 90 s 9 r epair 9-9 9.2.7 replacement of burner head 9.2.7.1 removal 1. Remove heater (see 8.7.1.1). 2. Remove combustion air fan (see 9.2.5.1). 3. Remove burner, flame sensor and glow pin (see 9.2.5.1). 4. Remove attachment screw of v-clamp (2, fig. 9-6) and pull off clamp. 5. Withdraw ...

  • Page 42: 90 / 90 S

    9 r epair t hermo 90 / 90 s 9-10 9.2.8 replacement of heat exchanger 9.2.8.1 removal 1. Remove heater (see 8.7.1.1). 2. Remove circulation pump (see 9.2.2.1). 3. Remove temperature limiter (see 9.2.3.1). 4. Remove temperature sensor (see 9.2.4.1). 5. Remove combustion air fan (see 9.2.5.1). 6 remove...

  • Page 43: Thermo 90

    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 www.Webasto.Com rev. 03/2000 907400 thermo 90 thermo 90 s workshop manual coolant ...