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  5. Workshop Manual

Webasto Thermo 90 ST Workshop Manual

Summary of Thermo 90 ST

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    Water heaters 09/2005 workshop manual thermo 90 s thermo 90 s-adr (transport of hazardous goods) thermo 90 st thermo 90 st-adr (transport of hazardous goods).

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    Thermo 90 s / thermo 90 st table of contents i table of contents 1 introduction 1.1 contents and purpose ........................................................................................................................... 101 1.2 meaning of signal words ..........................................

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    Table of contents thermo 90 s / thermo 90 st ii 6 function tests 6.1 general ................................................................................................................................................. 601 6.2 settings ...............................................................

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    Thermo 90 s / thermo 90 st table of contents iii 9 repair 9.1 general .................................................................................................................................................. 901 9.1.1 work on stripped-down components ...........................................

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    List of illustrations thermo 90 s / thermo 90 st iv list of illustrations 301 sequence of functions ............................................................................................................................... 302 501 general fault indications .........................................

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    Thermo 90 s / thermo 90 st 1 introduction 101 1 introduction 1.1 contents and purpose this workshop manual is designed to assist trained personnel with repairing both the petrol and the diesel versions of the thermo 90 s und thermo 90 st water heaters. The heater is only allowed to be operated with ...

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    1 introduction thermo 90 s / thermo 90 st 102 1.5 statutory regulations governing installation refer to the installation instructions for the statutory regulations if necessary..

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    Thermo 90 s / thermo 90 st 2 general description 201 2 general description thermo 90 s and thermo 90 st water heaters operate in conjunction with the vehicle’s own heating system and serve – to heat the cab, – to defrost the vehicle windows and – to preheat water-cooled engines. The water heater ope...

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    2 general description thermo 90 s / thermo 90 st 202 thermo 90 st heater 2.1 combustion air fan the combustion air fan supplies the air required for the combustion process from the combustion air inlet to the burner insert. Combustion air fan 2.2 heat exchanger in the heat exchanger, the heat genera...

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    Thermo 90 s / thermo 90 st 2 general description 203 2.3 temperature sensor the temperature sensor records the coolant temperature at the coolant outlet of the heater as an electrical resistance. This signal is fed to the control unit where it is processed. 2.4 temperature limiter the overheating gu...

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    2 general description thermo 90 s / thermo 90 st 204 page for notes.

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    Thermo 90 s / thermo 90 st 3 function description 301 3 function description (fig. 301) 3.1 switching on the “operating indicator” on the digital timer lights up when the “immediate heating” button is pressed. Or when switching on with the switch, the operating indicator in the switch lights up. The...

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    3 function description thermo 90 s / thermo 90 st 302 fig. 301 sequence of functions 3.4 switching off the operating indicator on the digital timer/switch goes out when the heater is switched off. The combustion process will be ended and the run-on phase will start. The circulating pump and the comb...

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    Thermo 90 s / thermo 90 st 3 function description 303 a glow plug b metering pump c combustion air fan d flame monitor e operation indicator light f circulating pump g vehicle fan 3.6 malfunctions 3.6.1 fault lock-out fuel is supplied for max. 240 seconds if the flame does not start to burn. Fuel is...

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    3 function description thermo 90 s / thermo 90 st 304 3.6.2 diagnosis after fault lock-out thermo 90 s and thermo 90 st check the fuses and plug connectors. 3.6.2.1 version with digital timer if the system is equipped with a standard clock, a fault message appears on the display of the digital timer...

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    Thermo 90 s / thermo 90 st 3 function description 305 page for notes.

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    Thermo 90 s / thermo 90 st 4 technical data 401 4 technical data except where limit values are specified, the technical data below refer to the usual heater tolerances of ±10% at an ambient temperature of +20 °c and at the rated voltage. Electrical components the control unit, motors for combustion ...

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    4 technical data thermo 90 s / thermo 90 st 402 page for notes.

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    Thermo 90 s / thermo 90 st 5 troubleshooting 501 5 troubleshooting 5.1 general this section describes how to identify and remedy faults on the thermo 90 s und thermo 90 st heater. Caution troubleshooting work demands precise knowledge of the structure and theory of operation of the various component...

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    5 troubleshooting thermo 90 s / thermo 90 st 502 5.3 fault indications on fault lock-out note if the system is operated with a switch, the nature of the fault is indicated by a flashing code on an indicator light during the run-on time of the heater. After five short signals, count the long flashes....

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    Thermo 90 s / thermo 90 st 5 troubleshooting 503 fig. 502 fault indications on fault lock-out (page 2 of 2) 5.4 visual check for assessing the burner the burner and the evaporator in the heater display specific characteristics when they must be replaced or do not have any fault source. The criteria ...

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    5 troubleshooting thermo 90 s / thermo 90 st 504 5.4.2 back wall with metal evaporator • the pilot flame outlet opening (fig. 504) must be clear otherwise no start will occur. Remedy replace burner • cracks, flaking as well as black or other discoloration of the evaporator do not lead to burner fail...

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    Thermo 90 s / thermo 90 st 6 function tests 601 6 function tests 6.1 general this section describes the tests conducted on the heater and its settings when it is installed and not installed to verify that it is in working order. Warning the heater must not be operated in enclosed areas such as garag...

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    6 function tests thermo 90 s / thermo 90 st 602 page for notes.

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    Thermo 90 s / thermo 90 st 7 circuit diagrams 701 7 circuit diagrams 7.1 general the circuit diagrams (figs. 701 to 704) show the possible circuits for the thermo 90 s heater with – standard clock – standard clock and separate circulating pump control – adr and switch – adr and switch, without power...

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    7 circuit diagrams thermo 90 s / thermo 90 st 702 fig. 701 system circuit for thermo 90 s, 12 and 24 v, with standard clock 2 8 11 10 1 12 7 4 h3 p2 h1 h6 30 85 86 87 87a k5 br br br rt br gn/ws rt/b l ge sw rt ws/b l vi bl vi/b l gr gn or or 58 15 1 2 58 15 f2 f3 x6 f1 bl br 30 30 31 31 sw rt sw rt...

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    Thermo 90 s / thermo 90 st 7 circuit diagrams 703 fig. 702 system circuit for thermo 90 s, 12 and 24 v, with standard clock and separate circulating pump control 2 8 11 10 1 12 7 4 h3 p2 h1 h6 30 30 85 85 86 86 87 87 87a 87a k5 k3 br br br rt rt br gn/ws rt/b l ge sw rt ws/b l vi bl vi/b l gr gn or ...

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    7 circuit diagrams thermo 90 s / thermo 90 st 704 fig. 703 system circuit for thermo 90 s-adr, 24 v, with switch temperature coding (temperature at water outlet): see table on page 302 vehicle fuse vehicle fan switch 1 3 4 a f e b 30 85 86 87 87a h2 s4 k5 br br br rt br gn/ws rt/b l ge sw rt ws/b l ...

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    Thermo 90 s / thermo 90 st 7 circuit diagrams 705 fig. 704 system circuit for thermo 90 s-adr, 24 v, with switch without power take-off temperature coding (temperature at water outlet): see table on page 302 vehicle fuse vehicle fan switch 1 3 4 a f e b 30 85 86 87 87a h2 s4 k5 br br br rt br gn/ws ...

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    7 circuit diagrams thermo 90 s / thermo 90 st 706 fig. 705 system circuit for thermo 90 st, 12 and 24 v, with standard clock ϑ ϑ temperature coding (temperature at water outlet): see table on page 302 digital timer p2: with positive at connection 10 = continuous operation with immediate heating conn...

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    Thermo 90 s / thermo 90 st 7 circuit diagrams 707 fig. 706 system circuit for thermo 90 st, 12 and 24 v, with standard clock and separate circulating pump control ϑ ϑ temperature coding (temperature at water outlet): see table on page 302 digital timer p2: with positive at connection 10 = continuous...

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    7 circuit diagrams thermo 90 s / thermo 90 st 708 fig. 707 system circuit for thermo 90 st-adr, 24 v, with switch ϑ ϑ temperature coding (temperature at water outlet): see table on page 302 vehicle fuse vehicle fan switch 1 3 4 cable cross-sections 7.5 - 15 m 0.75 mm 2 1.5 mm 2 2.5 mm 2 4.0 mm 2 1.5...

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    Thermo 90 s / thermo 90 st 7 circuit diagrams 709 fig. 708 system circuit for thermo 90 st-adr, 24 v, with switch without power take-off temperature coding (temperature at water outlet): see table on page 302 vehicle fuse vehicle fan switch 1 3 4 ϑ ϑ cable cross-sections 7.5 - 15 m 0.75 mm 2 1.5 mm ...

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    7 circuit diagrams thermo 90 s / thermo 90 st 710 page for notes.

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    Thermo 90 s / thermo 90 st 8 service work 801 8 service work 8.1 general this section describes the service work that can be carried out on the heater when it is installed. 8.2 work on the heater disconnect the main power cable from the vehicle’s battery before carrying out any work on the heater. T...

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    8 service work thermo 90 s / thermo 90 st 802 8.4 heater trial run the heater must not be operated in enclosed areas such as garages and workshops without an emissions extraction system, even if you use the timer. 8.5 service work the following service work is to be carried out after or before each ...

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    Thermo 90 s / thermo 90 st 8 service work 803 fig. 801 specimen installations for heater in a truck note the thermo 90 s and thermo 90 st heater is supplied with the control unit mounted on the combustion air fan. With non-return valve and thermostat without non-return valve 1 heat exchanger vehicle...

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    8 service work thermo 90 s / thermo 90 st 804 8.6 visual inspections and installation instructions 8.6.1 connection to the vehicle cooling system in thermostat circuits, only use thermostats which start to open at the heater should be installed in as low a position as possible to allow the heater an...

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    Thermo 90 s / thermo 90 st 8 service work 805 8.6.2.1 fuel extraction vehicles with diesel engines the fuel must be taken from the vehicle fuel tank or from a separate tank (figs. 803, 804 and 805). Fig. 803 webasto fuel extractor note the fitting must be made from metal! Fig. 804 fuel extraction fr...

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    8 service work thermo 90 s / thermo 90 st 806 the fuel extractor should not be located near the engine, as gas bubbles may form in the lines on account of heat radiated from the engine. This may cause problems during combustion. When installing the heater in a vehicle with fuel injection system, it ...

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    Thermo 90 s / thermo 90 st 8 service work 807 8.6.3 metering pump with damper the metering pump is a combined delivery, metering and shut-off system and is subject to certain installation criteria (figs. 802 and 808). 12 volts and 24 volts – petrol and diesel dp2 12 volts and 24 volts – diesel dp 30...

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    8 service work thermo 90 s / thermo 90 st 808 8.6.6 exhaust line the exhaust line (internal diameter 38 mm) can be installed with a length of 0.5 m to 5 m and several bends (360° altogether, minimum bending radius 85 mm). The exhaust muffler is essential and must be installed near the heater. An att...

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    Thermo 90 s / thermo 90 st 8 service work 809 8.7.2 changing the circulating pump note the process for changing the circulating pump is the same irrespective of whether the heater is installed or removed. Change as described in 9.2.2. 8.7.3 changing the temperature limiter note the process for chang...

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    Thermo 90 s / thermo 90 st 9 repair 901 9 repair 9.1 general this section describes the repair work which is permitted on the heater when it has been removed. Any further dismantling will invalidate the warranty. Only use the spare parts from the appropriate spare parts kits for assembling the heate...

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    9 repair thermo 90 s / thermo 90 st 902 9.2 dismantling and assembling 9.2.1 electrical connections (thermo 90 s) 9.2.1.1 disconnecting the electrical connections (plug connector x1) note all electrical connections are grouped together in the plug. Before removing a component, first disconnect the c...

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    Thermo 90 s / thermo 90 st 9 repair 903 9.2.2 changing the circulating pump 9.2.2.1 removal 1. Remove the heater (see 8.7.1.1). 2. Disconnect the electrical connections (see 9.2.1.1). 3. Remove the screws (4, fig. 902). 4. Remove the clip (3) and circulating pump (2). 5. Complete the work on strippe...

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    9 repair thermo 90 s / thermo 90 st 904 9.2.3 changing the temperature limiter 9.2.3.1 removal note the temperature limiter only has to be removed if it is being replaced with a new one. The function must be checked in the installed condition. 1. Remove the heater (see 8.7.1.1). 2. Disconnect the el...

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    Thermo 90 s / thermo 90 st 9 repair 905 fig. 903 changing the temperature limiter and temperature sensor 6 5 1 2 3 4 1 protective cap 2 clip 3 temperature limiter 4 heat exchanger 5 round sealing ring 6 temperature sensor note a thermo 90 st heater is shown. In the thermo 90 s heater, the control un...

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    9 repair thermo 90 s / thermo 90 st 906 9.2.5 changing the combustion air fan 9.2.5.1 removal 1. Remove the heater (see 8.7.1.1). 2. Disconnect the electrical connections (see 9.2.1.1). 3. Remove the screws (2, fig. 904). 4. Pull the combustion air fan (1) off the burner head (4) and remove together...

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    Thermo 90 s / thermo 90 st 9 repair 907 9.2.6 changing the burner, flame monitor and glow plug 9.2.6.1 removal 1. Remove the heater (see 8.7.1.1). 2. Remove the combustion air fan (see 9.2.5.1). 3. Remove the screw (5, fig. 905) and washer (4). 4. Remove the nuts (10) and pull off the bar (8). 5. Pu...

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    9 repair thermo 90 s / thermo 90 st 908 fig. 905 changing the burner, flame monitor and glow plug 1 burner 2 swirl orifice 3 burner head 4 washer 5 screw 6 glow plug 7 flame monitor 8 bar 9 insulation 10 nut (2) 11 grommet 12 grommet 13 grommet note a thermo 90 st heater is shown. The figure can als...

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    Thermo 90 s / thermo 90 st 9 repair 909 9.2.7 changing the burner head 9.2.7.1 removal 1. Remove the heater (see 8.7.1.1). 2. Remove the combustion air fan (see 9.2.5.1). 3. Remove the burner, flame monitor and glow plug (see 9.2.6.1). 4. Remove the mounting screw of the v-clamping collar (2, fig. 9...

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    9 repair thermo 90 s / thermo 90 st 910 9.2.8 changing the heat exchanger 9.2.8.1 removal 1. Remove the heater (see 8.7.1.1). 2. Remove the circulating pump (see 9.2.2.1). 3. Remove the temperature limiter (see 9.2.3.1). 4. Remove the temperature sensor (see 9.2.4.1). 5. Remove the combustion air fa...

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    Thermo 90 s / thermo 90 st 10 packing / storage / shipment 1001 10 packing / storage and shipment 10.1 general if the heater or its components are sent to webasto thermosysteme gmbh for testing or repair, it must be cleaned and packed in such a way that it is protected against damage during handling...

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    10 packing / storage / shipment thermo 90 s / thermo 90 st 1002 page for notes.