Repair manual

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– Improper installation or repair of Webasto heating and cooling systems can cause

fire or the leakage of deadly carbon monoxide leading to serious injury or death.

– Installation and repair of Webasto heating and cooling systems requires special

Webasto training, technical information, special tools and special equipment.

– NEVER attempt to install or repair a Webasto heating or cooling system unless you

have successfully completed the factory training course and have the technical skills,

technical information, tools and equipment required to properly complete the

necessary procedures.

– ALWAYS carefully follow Webasto installation and repair instructions and heed all

WARNINGS.

– Webasto rejects any liability for problems and damage caused by the system being

installed by untrained personnel.

Service and Repair Manual

Coolant Heaters

DBW 2010

DBW 2020

DBW 300

Circulation Pumps

U4810

U4814

U4846

U4851

Summary of content (72 pages)

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Service and Repair Manual Coolant Heaters DBW 2010 DBW 2020 DBW 300 Circulation Pumps U4810 U4814 U4846 U4851 – Improper installation or repair of Webasto heating and cooling systems can cause fire or the leakage of deadly carbon monoxide leading to serious injury or death. – Installation and repair of Webasto heating and cooling systems requires special Webasto training, technical information, special tools and special equipment.
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DBW 2010/2020/300 COOLANT HEATERS Contents TABLE OF CONTENTS Page 1. Introduction 7 1.1 1.2 1.3 1.4 1.5 Scope and Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Applicability of Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Meaning of Warnings, Cautions and Notes . . . . . . . . . . . .
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TABLE OF CONTENTS 5.3.5 5.3.6 5.3.7 5.3.8 DBW 2010/2020/300 COOLANT HEATERS Heater Switches Off By Itself During Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 Heater Smokes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 Heater Smokes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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DBW 2010/2020/300 COOLANT HEATERS 9. Repair TABLE OF CONTENTS 49 9.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 9.1.1 Work on Components after Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 9.1.1.1 Visual Inspection, General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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TABLE OF CONTENTS DBW 2010/2020/300 COOLANT HEATERS 9.2.17 Combustion Chamber, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61 9.2.17.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61 9.2.17.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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DBW 2010/2020/300 COOLANT HEATERS INTRODUCTION 1. INTRODUCTION 1.5 1.1 The general safety regulations for the prevention of accidents and the relevant operating safety instructions have to be observed at all times. SCOPE AND PURPOSE This repair shop manual is intended to support familiarized personnel in the repair of water heaters DBW 2010, 2020 and 300. SAFETY INFORMATION AND REGULATIONS "General Safety Regulations" beyond the scope of these regulations are detailed in the following.
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INTRODUCTION DBW 2010/2020/300 COOLANT HEATERS Installation Instructions for Webasto fuel tanks for the fuel supply of water heaters in vehicles: In the vicinity of the water heater a temperature of 85° C (185 °F) must not be exceeded under any circumstances (e.g. during body paint work). • in vehicles the installation is not permitted in the passengers’ or driver’s compartment. A violation of this temperature limit may cause permanent damage to the electronics.
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DBW 2010/2020/300 COOLANT HEATERS 2.
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GENERAL DESCRIPTION 1 2 3 4 DBW 2010/2020/300 COOLANT HEATERS 5 26 6 25 7 8 9 10 11 12 13 14 24 23 22 21 15 16 20 17 18 19 DBW 2010 1. Electronic control unit 10. Pre-heater 18. Coolant inlet 2. Motor 11. Coolant outlet 19. Heat exchanger 3. Electronic ignition unit 12. Bleeding valve 20. Combustion chamber 4. Coupling (clutch) 13. Ignition electrodes 21. Combustion air swirler 5. Combustion air fan 14. Fuel nozzle 22. Exhaust outlet 6. Toothed gearing 15.
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DBW 2010/2020/300 COOLANT HEATERS 1 2 3 4 26 5 6 25 8 24 10 GENERAL DESCRIPTION 9 18 13 23 22 7 14 21 15 16 11 17 20 19 DBW 2020 DBW 300 1. Electronic control unit 10. Pre-heater 18. Coolant inlet 2. Motor 11. Coolant outlet 19. Heat exchanger 3. Electronic ignition unit 12. Bleeding valve 20. Combustion chamber 4. Coupling (clutch) 13. Ignition electrodes 21. Combustion air swirler 5. Combustion air fan 14. Fuel nozzle 22. Exhaust outlet 6. Toothed gearing 15.
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GENERAL DESCRIPTION 2.1 2.1.1 DBW 2010/2020/300 COOLANT HEATERS PARTS OF THE HEATER 2.1.3 TEMPERATURE LIMITER (17) The temperature limiter is a thermostat that responds (opens) at a temperature of 95° C (203° F). The temperature limiter will automatically reset (closes) once temperature falls well below 95° C (203° F). Once the limiter has reset, the heater will have to be switched off and back on to restore operation.
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DBW 2010/2020/300 COOLANT HEATERS 2.1.5 FLAME DETECTOR (23) 2.1.6 GENERAL DESCRIPTION COMBUSTION AIR INTAKE (26) The air intake socket provides regulation of the combustion air quantity to the fuel quantity atomized by the high-pressure atomizer nozzle. Screw Photo Disc Flame Detector Locking screw Figure 5: Flame Detector and Photo Disc Combustion air The flame detector is a photosensitive, varying resistance element that supplies a “flame” or “no flame” signal to the control unit.
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GENERAL DESCRIPTION 2.1.7 DBW 2010/2020/300 COOLANT HEATERS COMBUSTION AIR FAN (5) AND MOTOR (2) The motor, through a coupling, drives the combustion air fan, and through a toothed gearing, the fuel pump. The combustion air fan supplies the air necessary for combustion. Rated motor r.p.m.
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DBW 2010/2020/300 COOLANT HEATERS 2.1.8 COUPLING (4) GENERAL DESCRIPTION 2.1.10 FUEL PUMP (24) The coupling (clutch) provides the mechanical connection between the motor and the combustion air fan. The fuel pump (single-staged toothed gear pump) delivers the fuel from the tank to the heater and brings it to a pressure of 10 ± 0.5 bar (145 ± 7 psi) for DBW 2010*, DBW 2020 and DBW 300. *DBW 2010 equipped with a 0.35 Gal/hr. nozzle only. For DBW 2010 with 0.40 Gal/hr.
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GENERAL DESCRIPTION DBW 2010/2020/300 COOLANT HEATERS 2.1.12 FUEL NOZZLE AND NOZZLE HOLDER (14) 2.1.14 ELECTRONIC IGNITION UNIT (3) The fuel atomizing nozzle is screwed into the nozzle holder. Under pressure, the fuel nozzle atomizes the fuel entering the combustion chamber. The electronic ignition unit develops high voltage of approximately 8000 volts to produce a spark at the tips of the ignition electrodes. The electronic ignition unit is only in operation during the starting phase.
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DBW 2010/2020/300 COOLANT HEATERS 2.1.16 COMBUSTION CHAMBER (20), COMBUSTION AIR SWIRLER (21) GENERAL DESCRIPTION 2.1.18 PREHEAT THERMOSTAT (7) The preheat thermostat is installed in the burner head on the back wall (DBW 2010) or on the photo disc (DBW 2020/300). It switches the nozzle holder pre-heating element (10) on which warms the fuel inside the nozzle holder to ensure fuel atomization in severe cold conditions. Within the burner tube of the combustion chamber, the air-fuel mixture is burned.
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GENERAL DESCRIPTION DBW 2010/2020/300 COOLANT HEATERS 2.1.20 COOLANT CIRCULATING PUMP The externally mounted circulation pump ensures proper coolant circulation in the vehicle and heater circuit. The pump is activated by the control unit to operate as long as the heater is in operation.
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DBW 2010/2020/300 COOLANT HEATERS 3. FUNCTIONAL DESCRIPTION 3.1 FUNCTIONAL DESCRIPTION The heater now starts the control idle period. Heater operation is resumed when the temperature drops below the lower operating point of the temperature control thermostat. SWITCH ON Upon switching on the Webasto heater, the operation indicator lamp (A) comes on, the heater motor (C) and the coolant circulating pump (B) begin to run.
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TECHNICAL DATA DBW 2010/2020/300 COOLANT HEATERS 4. TECHNICAL DATA FUEL FOR DBW SERIES (DIESEL/HEATING OIL/KEROSENE): Diesel fuel, heating oil and kerosene are suitable fuels for the heater. Unless tolerances are shown within the technical data table, a tolerance of ± 10% applies at an ambient temperature of +20 °C (+68 °F) and at the rated voltage and conditions. The Diesel fuel specified by the vehicle manufacturer is suitable as fuel for the heater.
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DBW 2010/2020/300 COOLANT HEATERS 4.1 TECHNICAL DATA TECHNICAL DATA OF THE HEATERS HEATER DBW 2010 DESIGN DBW 2020 DBW 300 Coolant heater with high-pressure nozzle HEAT OUTPUT kW (Btu/h) FUEL 13.0 (45,000) 23.3 (80,000) 30.0 (104,000) Diesel #1, #2, Arctic and Kerosene FUEL CONSUMPTION l/h (gal/h – US) (gal/h – Imp.) 1.5 (0.4) (0.3) 4.0 (1.2) (0.9) 3.0 (0.8) (0.
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TECHNICAL DATA 4.2 DBW 2010/2020/300 COOLANT HEATERS TECHNICAL DATA OF THE CIRCULATING PUMPS CIRCULATING PUMP FLOW RATE l/h (gal/min. – US) U 4810 U 4846 U 4814 U 4851 MP Pump 1600 (7.0) against 0.15 bar 700 (3.08) against 0.3 bar 5200 (22.9) against 0.2 bar 6000 (26.4) against 0.
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DBW 2010/2020/300 COOLANT HEATERS TROUBLESHOOTING 5. TROUBLESHOOTING 5.1 QUICK CHECK TROUBLESHOOTING MATRIX PROBLEM Switch On Control Light Blower Motor in Unit Blower Motor in Unit Blower Motor in Unit Coolant Circulating Pump Ignition Spark Combustion Combustion Combustion During Combustion During Combustion Heating Unit 5.
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TROUBLESHOOTING DBW 2010/2020/300 COOLANT HEATERS COMPONENT TEST PROCEDURES: Test Step Result If not Tester connected BATTERY LED (1) unit lights up - test input voltage at control terminals B4(+) and B2(-) - check battery connections - check battery voltage CONTROL THERMOSTAT LED (2) lights up - test switch/ timer - test control thermostat on heater Normal operating range - approx. 75 °C (167 °F) or higher open (no heat required) - approx.
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DBW 2010/2020/300 COOLANT HEATERS TROUBLESHOOTING NOTE: If flame does not stop when the FUEL SOLENOID VALVE button (7) is released, turn MOTOR switch (5) OFF to stop heater. Check and repair fuel solenoid valve accordingly. F. Once the manual test run has been successfully completed, set the heater switch or timer to OFF, remove the tester and reconnect the control unit. Once done, set the switch or timer to ON. If the heater or a heater component does not respond, the control unit is defective.
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TROUBLESHOOTING 5.3 5.3.1 DBW 2010/2020/300 COOLANT HEATERS INSTRUCTIONS FOR FAULT FINDING COMBUSTION STARTS IMMEDIATELY WHEN HEATER IS SWITCHED ON NO Electronic control unit defective YES 5.3.
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DBW 2010/2020/300 COOLANT HEATERS 5.3.3 TROUBLESHOOTING AFTER SWITCHING ON, THE HEATER SWITCHES OFF AFTER APPROX. 30 SECONDS ON FAULT NO Overheat fuse opened? Has temperature limiter (green wires) opened? YES Can you detect the buzzing sound of the ignition coil after approx. 20 seconds? Remove cause for release, e.g. lack of coolant; replace overheat fuse or allow temp. limiter to reset.
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TROUBLESHOOTING 5.3.4 DBW 2010/2020/300 COOLANT HEATERS HEATER STARTS ONLY AFTER SEVERAL STARTING ATTEMPTS NO YES 5.3.5 Does smoke emit from the exhaust pipe after failed attempts to start? Possible leakage in fuel suction or return fuel lines resulting in air pockets Continue fault finding according to section 5.3.
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DBW 2010/2020/300 COOLANT HEATERS 5.3.6 TROUBLESHOOTING HEATER SMOKES NO YES Is combustion air intake or exhaust outlet dirty? Are the gas passages (fins) of the heat exchanger highly soiled? Clean if necessary, correct installation according to instructions Clean according to instructions. (see Sec. 9.1.1.3) Does heater smoke only during start-up? Let heater burn freely (warm up to temp.
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TROUBLESHOOTING 5.3.
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DBW 2010/2020/300 COOLANT HEATERS 6. FUNCTIONAL ADJUSTMENTS FUNCTIONAL ADJUSTMENTS – Measure control unit power supply voltage – Operate heater for approximately 5 min. 6.1 GENERAL – Measure CO2 contents and compare with CO2 diagram This section describes the tests and adjustments on the heater in installed and removed condition to prove its serviceability. WARNING: The heater must not be operated in closed areas like garages or workshops with no exhaust ventilation facilities.
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FUNCTIONAL ADJUSTMENTS 6.2.2 DBW 2010/2020/300 COOLANT HEATERS FLAME DETECTOR RESISTANCE CHECK 6.2.3 NOTE: The glass bulb of the flame detector and the viewing glass of the window (refer to Fig. 22) are to be cleaned if contaminated. IGNITION ELECTRODE CHECK AND SETTING NOTE: The insulation body of the ignition electrodes must not show any damage. Damaged insulation of the electrodes requires their replacement. Setting ignition electrodes with a spacing beyond the tolerances shown in Fig.
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DBW 2010/2020/300 COOLANT HEATERS 6.2.4 FUNCTIONAL ADJUSTMENTS IGNITION COIL CHECK 6.2.5 WARNING: In some cases, high tension voltage of approx. 8,000 volts produced at the ignition electrodes can be fatal. A pressure gauge and the tester P/N 1302691A is required for performing this test. A suitable gauge with a range from 0 to 15 bar (0 to 220 PSI) can be procured from your authorized Webasto dealer. CAUTION: Do not operate the ignition coil without connection to the ignition electrodes.
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FUNCTIONAL ADJUSTMENTS 6.2.6 DBW 2010/2020/300 COOLANT HEATERS FUEL SOLENOID VALVE CHECK 6.2.7 NOZZLE BLOCK PRE-HEATER CHECK At a temperature of <0° C (<32° F) the heater cartridge in the nozzle block is activated. The heating period depends on the heat reflected within the combustion chamber. NOTE: A leaking solenoid valve seat or valve results in a rather long smoke emission period during run-down. In this case fuel keeps dripping through the fuel nozzle.
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P2 P1 S4 S3 R S1 S2 P2 GRAY 1 6 4 BLACK YELLOW 6 7 8 3 GRAY 3 5 1 6 4 BROWN RED BLACK YELLOW 5 6 7 8 4 2 BLUE/YELLOW 2 VIOLET 5 BROWN RED 5 4 2 3 BLUE/YELLOW 3 9 2 VIOLET RED DASH LAMPS (OPTIONAL) YELLOW RED BROWN DASH LAMPS (OPTIONAL) YELLOW RED BROWN VEHICLE IGNITION + RED/YELLOW RED WIRING CABLE TO THE HEATER WIRING CABLE TO THE HEATER BT F3 F2 F1 t° TO TIMER OPTION S1 S2 BROWN BROWN BROWN YELLOW RED BLUE GREEN BLACK RED K 86
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K L1 L2 BT DS E F1 F2 F3 F4 HR BT S1 BROWN RED BATTERY INDICATOR LIGHT IGNITION ELECTRODES FUSE 15A FUSE 10A FUSE 15A FUSE 20A HEATING ELEMENT (fuel pre-heater) RELAY (fuel pre-heater) SOLENOID VALVE IGNITION COIL BLACK DS BROWN RED RED RED GREEN X1 X2 S4 S3 M1 M2 R S1 S2 X1 J H G F E A C D 1 2 3 4 7 6 5 COOLANT CIRCULATION PUMP HEATER MOTOR FLAME DETECTOR ON / OFF SWITCH (heater) PREHEAT (FUEL) THERMOSTAT (green and blue wires) CONTROL THERMOSTAT (white and orange wires) TE
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BLUE BLACK X1 X2 X3 S4 CONTROL THERMOSTAT (green and red wires) TEMPERATURE LIMITER (green and green wires) 9-PIN HARNESS CONNECTOR (round) 2-WAY CONNECTOR 2-WAY CONNECTOR A B C GREEN S3 RED BLACK GREEN BROWN BROWN BROWN RED RED BATTERY INDICATOR LIGHT IGNITION ELECTRODES FUSE 15A FUSE 20A FUSE 15A OVERHEAT FUSE 138°C FUSE 30A FUSE 15A RELAY (on / off switch) SOLENOID VALVE IGNITION COIL COOLANT CIRCULATION PUMP HEATER MOTOR FLAME DETECTOR ON / OFF SWITCH (heater) S1 DS BROWN G BROWN H
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X1 X2 X3 S4 S3 BT DS E F1 F2 F3 F4 F5 F6 HR K1 K2 L1 L2 M1 M2 R S1 S2 BT RED BLACK GREEN A B C G BROWN H WHITE J D BROWN RED RED BLUE BLACK GREEN BROWN BROWN BROWN RED RED BATTERY INDICATOR LIGHT IGNITION ELECTRODES FUSE 15A FUSE 20A FUSE 15A OVERHEAT FUSE 138°C FUSE 30A FUSE 15A HEATING ELEMENT (fuel pre-heater) RELAY (on / off switch) RELAY (fuel pre-heater) SOLENOID VALVE IGNITION COIL COOLANT CIRCULATION PUMP HEATER MOTOR FLAME DETECTOR ON / OFF SWITCH (heater) PREHEAT (FUEL) THER
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X1 X2 S4 S3 I K1 K2 L1 L2 M1 M2 R S1 S2 BT DS E F1 F2 F3 F4 F5 HR BT WHITE GREEN BLACK RED BROWN J D C B A G H BROWN GRAY GREEN BLACK BLUE BROWN BROWN BATTERY INDICATOR LIGHT IGNITION ELECTRODES FUSE 15A FUSE 20A FUSE 15A OVERHEAT FUSE 138°C FUSE 30A HEATING ELEMENT (fuel pre-heater) INERTIA SAFETY SWITCH RELAY (on / off switch) RELAY (fuel pre-heater) SOLENOID VALVE IGNITION COIL COOLANT CIRCULATION PUMP HEATER MOTOR FLAME DETECTOR ON / OFF SWITCH (heater) PREHEAT (FUEL) THERMOSTAT
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P1 I K1 K2 L1 L2 BT E F1 F2 F3 F4 F5 HR 1 6 4 RED BLACK YELLOW 6 7 8 BATTERY IGNITION ELECTRODES FUSE 15A FUSE 20A FUSE 15A OVERHEAT FUSE 138°C FUSE 30A HEATING ELEMENT (fuel pre-heater) INERTIA SAFETY SWITCH RELAY (heater activation) RELAY (fuel pre-heater) SOLENOID VALVE IGNITION COIL 5 3 2 9 WHITE GREEN BLACK RED BROWN BROWN GRAY BLUE/YELLOW VIOLET VIOLET BROWN BROWN RED 5 4 3 2 TO TIMER BT C D J B A G H X1 X2 X3 X4 S4 S3 M1 M2 P1 R S2 RED ORANGE BLUE WIRING
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P2 I K1 K2 L1 L2 BT E F1 F2 F3 F4 F5 HR 5 BROWN 4 6 4 RED BLACK YELLOW 11 2 1 BATTERY IGNITION ELECTRODES FUSE 15A FUSE 20A FUSE 15A OVERHEAT FUSE 138°C FUSE 30A HEATING ELEMENT (fuel pre-heater) INERTIA SAFETY SWITCH RELAY (heater activation) RELAY (fuel pre-heater) SOLENOID VALVE IGNITION COIL 1 BROWN 12 2 3 X3 WHITE GREEN BLACK C D J B A G H X1 X2 X3 X4 BROWN BLUE X2 2 1 3 3 1 K2 86 85 87 BROWN t° 30 BROWN S2 HR BROWN GRAY 2 5 BROWN WHITE GREEN 4 1 2
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CIRCUIT DIAGRAMS 7.
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DBW 2010/2020/300 COOLANT HEATERS 8. SERVICING 8.1 every four weeks for 20 minutes setting the heating system to "warm". This avoids difficulties in the startup. GENERAL • at least once a year, in case of contaminated fuel more often, the fuel filter or filter cartridge as well as the filter screen of the fuel pump must be replaced to avoid malfunctions. This section describes the servicing work that can be carried out on the heater when it is installed. 8.
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SERVICING DBW 2010/2020/300 COOLANT HEATERS 3. Torque nuts (3) to: DBW 2010: 4.0 - 4.5 Nm (35.5 - 40.0 lb-in.). DBW 2020/300: 7.5 - 8.5 Nm (66 - 75 lb-in.). 1 2 3 4 4. Reconnect electrical connections to the control unit. Cotter pin Hinge Bolts (2) Nut (2) Burner head 1 2 3 4 NOTE: Depending on the burner head direction of swing, the cotter pin may be located to the opposite side. CAUTION: Always use hinge bolts to lock burner head in place.
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DBW 2010/2020/300 COOLANT HEATERS 8.6 VISUAL INSPECTIONS AND REGULATIONS FOR INSTALLATION SERVICING to DIN 73378 observing the applicable jointing instructions. Basic rules for the routing of fuel lines are: 8.6.1 CONNECTION TO VEHICLE COOLING SYSTEM • Protect against undue temperatures. The installation of the heater should be in a location as low as possible to ensure self-venting of the heater and circulation pump. This applies in particular for the circulation pump because it is not self-priming.
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SERVICING DBW 2010/2020/300 COOLANT HEATERS The combustion air inlet must be located so that no exhaust fumes can enter. – replacement of temperature limiter If the heater is located near the fuel tank in a common installation compartment, combustion air must be taken in from and the exhaust routed to the exterior. The feedthrough holes must be sealed against splash water.
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DBW 2010/2020/300 COOLANT HEATERS 8.7.2 TEMPERATURE LIMITER, REPLACEMENT WARNING: The igniter box operates on high voltage. Prior to replacement of flame detector, disconnect electrical connectors of cable harness in vehicle to avoid lethal accidents. NOTE: The replacement procedure for the temperature limiter is identical with the heater installed or removed. Perform replacement in accordance with 9.2.3. 8.7.8 8.7.
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SERVICING DBW 2010/2020/300 COOLANT HEATERS 8.8.2 heater has responded because the heater has not been bled properly. When switching the heater on the fuel pump pulls fuel from the fuel tank to prime the complete fuel supply system. Reset temperature limiter (allow temperature limiter to cool, self resetting) and repeat complete bleeding procedure. Should no combustion be achieved with the first start attempt, switch the heater off and on again.
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DBW 2010/2020/300 COOLANT HEATERS REPAIR 9. REPAIR 9.1.1.1 VISUAL INSPECTION, GENERAL 9.1 • Examine all components for damages (cracks, deformation, wear, etc.) and replace as necessary. GENERAL INFORMATION • Examine connectors and wiring for corrosion, loose contacts, wrong crimping, etc. and repair as necessary. This section describes the repairs that may be performed on the heaters DBW 2010, 2020 and 300 when removed. Any further disassembly will void the warranty.
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REPAIR DBW 2010/2020/300 COOLANT HEATERS 9.2 9.1.1.4 COMBUSTION AIR FAN WHEEL, VISUAL INSPECTION 9.2.1 – The fan wheel has to be checked for contamination, traces of grinding and cracks. DISASSEMBLY AND ASSEMBLY OVERHEAT FUSE, REPLACEMENT 9.2.1.1 REMOVAL DBW 2010 ONLY: 1. Disconnect electrical connection to overheat fuse at connector block. The clearance between the blower wheel and blower case must be measured (measurable with a feeler gauge) at the narrowest point. Clearance = 0.15/-0.05 mm. 2.
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DBW 2010/2020/300 COOLANT HEATERS 9.2.3 TEMPERATURE LIMITER, REPLACEMENT REPAIR 9.2.4 9.2.3.1 REMOVAL CONTROL UNIT, REPLACEMENT 9.2.4.1 REMOVAL 1. Disconnect electrical connection to temperature limiter at connector block. 1. Disconnect all electrical connections from control unit. 2. Turn counterclockwise to remove temperature limiter (item 3, Fig. 36). 2. Carefully withdraw control unit from holding clip or slide out with holding clip (Fig. 37). 9.2.3.2 INSTALLATION 9.2.4.2 INSTALLATION 1.
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REPAIR DBW 2010/2020/300 COOLANT HEATERS 3 2 1 1 Control Unit 1553 2 Holding Clip 3 Burner head Figure 37: Control Unit Removal / Installation 1 2 3 4 Cotter pin Hinge Bolts (2) Nut (2) Burner head 1 2 3 4 NOTE: Depending on the burner head direction of swing, the cotter pin may be located to the opposite side. CAUTION: Always use hinge bolts to lock burner head in place. Figure 38: Burner Head Removal / Installation Webasto Thermo & Comfort N.A., Inc. 52 www.techwebasto.
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DBW 2010/2020/300 COOLANT HEATERS 9.2.6 FUEL VALVE AND SOLENOID, REPLACEMENT REPAIR 9.2.7 9.2.6.1 REMOVAL FUEL PUMP, REPLACEMENT 9.2.7.1 REMOVAL 1. Swing open or remove burner head (see Sec. 9.2.5). 1. Remove burner head (see Sec. 9.2.5). 2. Disconnect the ignition leads from the ignition electrodes. 2. Disconnect electrical leads from solenoid valve, flame detector, nozzle pre-heater and ignition electrodes. 3. Loosen the retaining clamp bolt and dismount the ignition electrodes. 3.
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REPAIR DBW 2010/2020/300 COOLANT HEATERS Nozzle Holder Nozzle Figure 41: 9.2.9 Nozzle Replacement FLAME DETECTOR, REPLACEMENT 9.2.9.1 REMOVAL 1. Swing burner head open (see Sec. 8.5.1). 2. Remove screw and lock washer and slide flame detector out of slot in disc. 3. Disconnect electrical leads to flame detector. Figure 40: Fuel Pump Replacement 9.2.9.2 INSTALLATION 1. Connect electrical leads to new flame detector. 9.2.8 2.
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DBW 2010/2020/300 COOLANT HEATERS 9.2.10 IGNITION ELECTRODES, REPLACEMENT REPAIR 9.2.11 IGNITION COIL, REPLACEMENT NOTE: If the ignition is faulty, check also the flame detector (see Sec. 6.2.2). 9.2.10.1 REMOVAL 1. Swing burner head open (see Sec. 8.5.1). 2. Disconnect the ignition leads from the ignition electrodes. 9.2.11.1 REMOVAL 1. Swing open or remove burner head (see Sec. 9.2.5). 3. Loosen the retaining clamp bolt and dismount the ignition electrodes. 2.
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REPAIR DBW 2010/2020/300 COOLANT HEATERS 9.2.12 DRIVE MOTOR, REPLACEMENT 9.2.12.2 INSTALLATION NOTE: Recessed edge of mounting flange (item 3, Fig. 45) must be oriented towards top. All items must be aligned as before disassembly. 9.2.12.1 REMOVAL NOTE: Take note of alignment of all components before disassembly. 1. Attach mounting flange (3) to drive motor (2). 1. Move ignition coil out of the way. See Sec. 9.2.11 for guidance. 2. Tighten screws (8) to 5 - 6 Nm (44 - 53 lb-in.). 3.
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DBW 2010/2020/300 COOLANT HEATERS 9.2.13 COMBUSTION AIR FAN, REPLACEMENT REPAIR 9.2.13.2 INSTALLATION DBW 2010 ONLY: NOTE: For replacement of the combustion air fan the burner may be left installed. In removed condition ensure that igniter electrodes are not bent and nozzle is not damaged. 1. Assemble bearings and components if required (see Sec. 9.2.15). 2. Push fan with shaft through bearings and spacer of housing (item 5, Fig. 46) 3. Install washer (6), drive gear (7) and lock-nut (8). 9.2.13.
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REPAIR DBW 2010/2020/300 COOLANT HEATERS 9.2.14 FAN REPLACEMENT 9 8 6 DBW 2010 5 4 3 10 2 1 7 9 6 8 5 4 3 10 2 1 7 DBW 2020/300 Figure 46: Fan Replacement Webasto Thermo & Comfort N.A., Inc. 58 www.techwebasto.
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1 1 2 3 4 5 Figure 47: www.webasto.us 3 4 5 Fan Large spring washer Small spring washer Washer (black) Retaining ring 2 6 6 7 8 9 10 Bearing Carrier housing Spacer Bearing Wave-spring washer 7 11 12 13 14 8 59 10 DBW 2010 11 12 13 14 Retaining ring Washer (Brass color) Drive gear Lock-nut 9 DBW 2010/2020/300 COOLANT HEATERS REPAIR 9.2.15 FAN SHAFT, BEARINGS AND GEARING, EXPLODED VIEW (DBW 2010) Exploded view - fan support assembly - DBW 2010 Webasto Thermo & Comfort N.A., Inc.
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REPAIR DBW 2010/2020/300 COOLANT HEATERS Back wall housing Washer (Brass color) Drive gear Lock-nut 6 7 8 9 10 1 1 2 3 4 5 2 3 Retaining ring Motor carrier Wave-spring washer Shaft Roll pins 4 5 6 7 8 Bearing Retaining ring Fan Bearing O-ring 9 10 11 12 13 14 11 DBW 2020 / 300 12 13 14 9.2.16 FAN SHAFT, BEARINGS AND GEARING, EXPLODED VIEW (DBW 2020 / DBW 300) Figure 48: Exploded view - fan support assembly - DBW 2020/300 Webasto Thermo & Comfort N.A., Inc. 60 www.techwebasto.
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DBW 2010/2020/300 COOLANT HEATERS REPAIR 9.2.17 COMBUSTION CHAMBER, REPLACEMENT 9.2.18 HEAT EXCHANGER, REPLACEMENT 9.2.17.1 REMOVAL 9.2.18.1 REMOVAL 1. Swing burner head open (see Sec. 8.5.1). 1. Disconnect cables from temperature control thermostat, temperature limiter and overheat fuse. 2. Withdraw combustion chamber (Fig. 50) from heat exchanger and remove. 2. Detach cables from heat exchanger. 3. Remove burner head (see Sec. 9.2.5).
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REPAIR 9.3 DBW 2010/2020/300 COOLANT HEATERS COOLANT CIRCULATING PUMP REPAIR 9.3.4 INSTALLING 1. Mount the pump. A defective coolant pump may cause the heater to overheat. The heater’s overheat protection is likely to respond in this case. 2. Connect coolant hoses to pump and tighten hose clamps. 3. Remove hose clamping pliers if used. 9.3.1 REMOVAL 4.
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DBW 2010/2020/300 COOLANT HEATERS REPAIR U4851 U4814 9 38 38 10 9 10 38 38 12 12 11 11 8 8 5 6 7 5 7 4 4 3 3 2 2 1 1 1 2 3 4 6 Screw - Impeller Housing Impeller Housing Nut - Impeller Impeller Figure 54: 5 6 7 8 Spring Seal Stationary Ceramic Seal Rubber Seal O-ring 9 10 11 12 Screw - Pump Base Washer - Pump Base Pump Base Rubber Shaft Boot U4814 and U4851 Circulation Pump - Exploded View U 4846 U 4846 Pump Only: Pump is magnetically coupled to the motor (no shaft seals to
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REPAIR 9.4 9.4.1 DBW 2010/2020/300 COOLANT HEATERS MP SCHOOL BUS CIRCULATION PUMP 9.4.3 ASSEMBLING 1. Connect pump motor to a power source. With a strip of very fine emery cloth, polish the pump shaft to remove any contamination. REMOVAL 1. Drain the coolant. Alternatively, the hoses leading to the pump can be pinched closed with hose clamping pliers. 2. Remove power source from pump motor. 3. Assemble pump with all parts in order as shown in Fig. 53. 2.
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DBW 2010/2020/300 COOLANT HEATERS INSTRUMENTS AND TOOLS 10. INSTRUMENTS AND TOOLS 10.3 CO2 TEST APPARATUS 10.1 SETTING GAUGE Used for sampling and measuring the CO2 content of the exhaust gases. Used for setting the gap between the points of the electrodes and the distance from the fuel nozzle. In the case of irregularities of the combustion process or after major repairs, the CO2 content should be measured and adjusted as necessary. Part Number 310646 10.
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INSTRUMENTS AND TOOLS DBW 2010/2020/300 COOLANT HEATERS 10.5 NOZZLE WRENCH 10.7 GREASE AND LOCKING VARNISH Used for replacing high-pressure fuel nozzle. • LDS 18 Special - used for lubricating the reduction gearing of the fuel pump drive. Part Number 66971A • Dielectric Silicone Grease - used to protect electrical terminals and connectors from corrosion. • Red Locking Varnish - used to indicate setting positions such as on the air intake locking screw once adjusted. 20 38 14 ams P/N 5 gr 4 10.
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DBW 2010/2020/300 COOLANT HEATERS PRODUCT INFORMATION 11. PRODUCT INFORMATION Product Information 11.1 ISS “WHITE” TIMER FOR THE SCHOLASTIC HEATER™ Category: Thermosystems Document Number: PI007RC Date Posted: 02/02/2007 Description: NOI (NO OPERATOR INTERFACE) “WHITE” TIMER INSTALLATION / OPERATION Overview The “White” timer is a 7-day NOI (no operator interface) timer. This means you can set this timer to specific needs and the timer will do the rest.
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Product Information PRODUCT INFORMATION DBW 2010/2020/300 COOLANT HEATERS Category: Thermosystems Document Number: PI007RC Date Posted: 02/02/2007 Description: NOI (NO OPERATOR INTERFACE) “WHITE” TIMER INSTALLATION / OPERATION Wiring diagram - NOI Timer with optional Toggle Switch Setting the Timer The timer is a 7-day NOI (no operator interface) timer. This means you can set this timer to specific needs and the timer will do the rest.
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Product Information DBW 2010/2020/300 COOLANT HEATERS PRODUCT INFORMATION Category: Thermosystems Document Number: PI007RC Date Posted: 02/02/2007 Description: NOI (NO OPERATOR INTERFACE) “WHITE” TIMER INSTALLATION / OPERATION Operation in manual mode: The largest button on the timer is the “Manual” button. At the bottom of the “LCD” screen you will see a small line that moves as you push this button. Underneath the small line you will see the corresponding function “On” “Auto” “Off”.
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WARRANTY WARRANTY COVERAGE DBW 2010/2020/300 COOLANT HEATERS AND LIMITATIONS Webasto Product North America, Inc. (herein after referred to Webasto) warrants their heaters and heater kits against defects in material and workmanship for two (2) years effective at the time of installationor vehicle registration date for Original Equipment installations (OE). This warranty period may not exceed three (3) years from the original date of sale by Webasto.
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WEBASTO THERMO & COMFORT N.A., INC. 15083 North Road Fenton, MI 48430 Technical Assistance Hot-line USA: (800) 860-7866 Canada: (800) 667-8900 Org. 01/2008 Rev. 04/2013 P/N LIT669745B www.techwebasto.com www.webasto.