Webasto | DBW 46 | Repair manual | Webasto DBW 46 Repair manual

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.
– 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.
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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Additional Documentation to be used. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Safety Information and Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.5.1 General Safety Notes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1.6 Legal Provisions for Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1.7 Corrections and Improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2. General Description
2.1
9
Parts of the Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1.1 Electronic Control Unit (1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1.2 Overheat Fuse (15) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1.3 Temperature Limiter (17) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1.4 Temperature Control Thermostat (16) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1.5 Flame Detector (23). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.1.6 Combustion Air Intake (26) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.1.7 Combustion Air Fan (5) and Motor (2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.1.8 Coupling (4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.1.9 Toothed Gearing (6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.1.10 Fuel Pump (24) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.1.11 Fuel Control Valve and Solenoid (8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.1.12 Fuel Nozzle and Nozzle Holder (14) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.1.13 Fuel Line Connections (25) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.1.14 Electronic Ignition Unit (3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.1.15 Ignition Electrodes (13) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.1.16 Combustion Chamber (20), Combustion Air Swirler (21) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1.17 Heat Exchanger (19) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1.18 Preheat Thermostat (7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1.19 Pre-heater Cartridge (10). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.1.20 Coolant Circulating Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
3. Functional Description
3.1
3.2
3.3
19
Switch ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Heating Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Switch Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4. Technical Data
4.1
4.2
4.3
20
Technical Data of the Heaters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Technical Data of the Circulating Pumps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Permissible Extension of the Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
5. Troubleshooting
23
5.1
5.2
Quick Check Troubleshooting Matrix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Tester Instructions (Tester P/N 1302691A) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.2.1 Test Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5.3 Instructions for Fault Finding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5.3.1 Combustion Starts Immediately When Heater Is Switched ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5.3.2 Heater Does Not Start When Switched ON . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5.3.3 After Switching ON, The Heater Switches OFF after Approx. 30 Seconds On Fault . . . . . . . . . . . . . . . . . . . . . 27
5.3.4 Heater Starts Only After Several Starting Attempts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
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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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Heater Cannot Be Switched Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
6. Functional Adjustments
6.1
6.2
31
General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
6.2.1 Adjustment of CO2 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
6.2.2 Flame Detector Resistance Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
6.2.3 Ignition Electrode Check and Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
6.2.4 Ignition Coil Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
6.2.5 Fuel Pump Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
6.2.6 Fuel Solenoid Valve Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
6.2.7 Nozzle Block Pre-heater Check. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
7. Circuit Diagrams
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
35
DBW 2010 12 V and 24 V - Early Canadian Version. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
DBW 2010 12 V and 24 V - Present North American Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
DBW 2020 / 300 12 V and 24 V - without Nozzle Preheat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
DBW 2020 / 300 12 V and 24 V - with Nozzle Preheat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
Scholastic Heater 12 V - with On/Off Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Scholastic Heater 12 V - with 7-Day Timer Model 1529 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
Scholastic Heater 12 V - with 7-Day Timer Model 1531 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Control Unit - Identification of Terminals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
8. Servicing
43
8.1
8.2
8.3
8.4
8.5
General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Heater Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Vehicle Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Heater Test Run. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
Maintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
8.5.1 Burner Head Opening and Closing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
8.6 Visual Inspections and Regulations for Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
8.6.1 Connection to Vehicle Cooling System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
8.6.2 Connection to Vehicle Fuel System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
8.6.2.1 Fuel Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
8.6.2.2 Fuel Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
8.6.3 Combustion Air Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
8.6.4 Exhaust Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
8.7 Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
8.7.1 Heater, Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
8.7.1.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
8.7.1.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
8.7.2 Temperature Limiter, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
8.7.3 Temperature Thermostat, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
8.7.4 Overheat Fuse, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
8.7.5 Burner Head, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
8.7.6 Ignition Coil, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
8.7.7 Flame Detector (Photo Eye), Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
8.7.8 Combustion Chamber, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
8.8 First Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
8.8.1 Water Circuit, Bleeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .47
8.8.2 Fuel Supply System, Bleeding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
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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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
9.1.1.2 Combustion Chamber, Visual Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
9.1.1.3 Heat Exchanger, Visual Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
9.1.1.4 Combustion Air Fan Wheel, Visual Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
9.2 Disassembly and Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
9.2.1 Overheat Fuse, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
9.2.1.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
9.2.1.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
9.2.2 Temperature Control Thermostat, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
9.2.2.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
9.2.2.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
9.2.3 Temperature Limiter, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
9.2.3.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
9.2.3.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
9.2.4 Control Unit, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
9.2.4.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
9.2.4.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
9.2.5 Burner, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
9.2.5.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
9.2.5.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
9.2.6 Fuel Valve and Solenoid, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
9.2.6.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
9.2.6.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
9.2.7 Fuel Pump, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
9.2.7.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
9.2.7.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
9.2.8 Fuel Nozzle, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9.2.8.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9.2.8.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9.2.9 Flame Detector, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9.2.9.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9.2.9.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
9.2.10 Ignition Electrodes, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
9.2.10.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
9.2.10.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
9.2.11 Ignition Coil, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
9.2.11.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
9.2.11.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
9.2.12 Drive Motor, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
9.2.12.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
9.2.12.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
9.2.13 Combustion Air Fan, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
9.2.13.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
9.2.13.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
9.2.14 Fan Replacement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
9.2.15 Fan Shaft, Bearings and Gearing, Exploded View (DBW 2010) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
9.2.16 Fan Shaft, Bearings and Gearing, Exploded View (DBW 2020 / DBW 300) . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
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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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
9.2.18 Heat Exchanger, Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
9.2.18.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
9.2.18.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61
9.3 Coolant Circulating Pump Repair. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
9.3.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
9.3.2 Disassembling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
9.3.3 Assembling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
9.3.4 Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
9.4 MP School Bus Circulation Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
9.4.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
9.4.2 Disassembling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
9.4.3 Assembling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
9.4.4 Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
10.Instruments and Tools
10.1
10.2
10.3
10.4
10.5
10.6
10.7
65
Setting Gauge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
Tester . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
CO2 Test Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
Smoke Number Test Apparatus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .65
Nozzle Wrench . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
Fuel Pressure Gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
Grease and Locking Varnish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66
11.Product Information
67
11.1 ISS “White” Timer for the Scholastic Heater™ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .67
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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.
The water heater may only be operated with the fuel
specified on the model plate and the relevant designated
type of electrical connection.
The specific safety regulations applicable to this manual
are highlighted in the individual chapters by Warnings,
Cautions, and Notes.
1.2
1.5.1
APPLICABILITY OF MANUAL
The year of first operation must be permanently marked
on the identification label by removing the relevant
number of the year.
This manual is applicable only for heaters identified on
the title page.
1.3
The heaters are cleared for heating the vehicle engine
and the passenger cabin. The use of the heater in
vehicles not subject to the EU Directive 70/156/EEC (e.g.
ships) is partly governed by regional regulations.
MEANING OF WARNINGS, CAUTIONS AND
NOTES
WARNINGS, CAUTIONS, and NOTES in this manual have
the following meaning:
The heater may only be fitted in vehicles or in
independent heating systems with a minimum coolant
capacity of 10 liters for DBW 2010 and 15 liters for DBW
2020 and 300.
DANGER: This heading and text style is
used to highlight that non-compliance with
instructions or procedures will cause
injuries or lethal accidents to personnel.
The heater must not be installed in the passenger or
driver compartments of vehicles. Should the heater
nevertheless be installed in such a compartment, the
installation box must be sealed tight against the vehicle
interior.
WARNING: This heading and text style is
used to highlight that non-compliance with
instructions or procedures may cause
injuries or lethal accidents to personnel.
There must be sufficient ventilation of the installation box
from the exterior in order not to exceed a maximum
temperature of 85° C (185 °F) in the installation box.
Excessive temperatures may cause malfunctions.
CAUTION: This heading and text style is
used to highlight that non-compliance with
instructions or procedures may cause
damage to equipment.
WARNING: Due to the danger of
poisoning and suffocation the heater must
not be operated, not even with timed
operation, in enclosed areas such as
garages or workshops not equipped with
an exhaust venting facility.
NOTE: This heading and text style is used to
highlight and draw attention to information we
feel you would like to have. It could have to do
with procedures and tips that will help you work
more efficiently.
1.4
WARNING: At filling stations and fuel
depots the heater must be switched off to
prevent explosions.
ADDITIONAL DOCUMENTATION TO BE USED
This workshop manual contains all information and
procedures necessary for the repair of heaters DBW
2010, 2020 and 300.
CAUTION: Where flammable fumes or
dust may build up (e.g. in the vicinity of
fuel, coal, wood, cereal depots, or similar
installations) the heater must be switched
off to prevent explosions.
The heater must not be operated near
flammable materials such as dry grass and
leaves, cardboard boxes, paper, etc.
The use of additional documentation is normally not
necessary.
Operating instructions and installation instructions may
be used as complementary information as necessary.
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GENERAL SAFETY NOTES
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Webasto Thermo & Comfort N.A., Inc.
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.
• the fuel filler neck must not be located in the
passengers’ or driver’s compartment of any vehicle.
When checking the cooling water level proceed in
accordance with the vehicle manufacturer’s instructions.
• fuel containers must either be equipped with a vent
cap or any other type of ventilation (vent line).
The water in the heating circuit of the heater must
contain a minimum of 20% of a quality brand antifreeze.
Only vent caps in accordance with DIN 73400 may be
used.
Additives in the heating circuit must not affect metals,
plastics and rubber and must leave no deposits.
All fuel containers offered in the Webasto Accessories
Catalogue are suitable for a maximum operating pressure
of 0.15 bar overpressure.
The opening pressure in the vehicle cooling system normally indicated on the radiator filler cap - must be
between 0.4 and 2.0 bar above operating pressure (also
applicable to separate heating circuits).
1.6
All fuel containers offered in the Webasto Accessories
Catalogue are subjected during manufacture to
individual pressure testing with at least 0.3 bar
overpressure.
LEGAL PROVISIONS FOR INSTALLATION
• The operational state of the heater, i.e. at least an
indication "on" or "off" must be easily and clearly
visible.
DBW series heaters have been type-tested and approved
in accordance with EG Directives 72/245/EWG (EMV) and
2001/56/EG (heater) with the following EG permit
numbers:
For heaters in vehicles not ruled by the EU Directive but
other regulations, the acceptance by the relevant
authority is required as applicable.
e1*2001/56*0006*xx
Installation is governed above all by the provisions in
Annex VII of Directive 2001/56/EC.
1.7
CORRECTIONS AND IMPROVEMENTS
Deficiencies, improvements, or proposals for correction
of this workshop manual are to be mailed to:
NOTE: The provisions of these Directives are
binding within the territory governed by EU
Directive 70/156/EEC and should similarly be
observed in countries without specific
regulations.
WEBASTO PRODUCT NORTH AMERICA, INC.
TECHNICAL DOCUMENTATION GROUP
15083 NORTH ROAD
FENTON MI 48430
(Extract from Directive 2001/56/EC Annex VII)
“1.7.1. A clearly visible indicator within the user's field of
vision must show when the heater is switched On or
Off.”
NOTE: For further notes and provisions
relating to the installation of the heater in
vehicles, refer to the installation instructions.
IMPORTANT!
Failure to follow the installation instructions and
the notes contained therein will lead to all liability
being refused by Webasto The same applies if
repairs are carried out incorrectly or with the use of
parts other than genuine spare parts. This will
result in the invalidation of the type approval for
the heater and therefore of its homologation / EC
type licence.
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DBW 2010/2020/300 COOLANT HEATERS
2. GENERAL DESCRIPTION
GENERAL DESCRIPTION
For control and monitoring, the heater includes:
– a control unit
The water heaters Webasto DBW 2010, DBW 2020,
DBW 300 and Scholastic Heater™ are used in
combination with the vehicle’s own heating installation
to:
– an overheat fuse (non-reset)
– a temperature limiter
– a temperature control thermostat
– a flame detector (photo eye)
– heat the passenger compartment
– defrost the windshield
– preheat water-cooled engines
A coolant circulating pump is installed directly to the
heater or inside an enclosure or on a tray mount.
– in self-contained cargo heating applications
The heaters may also be equipped with an optional cold
starting aid consisting of:
The water heater operates independent from the vehicle
engine and is connected to the vehicle cooling system,
the fuel system and the electrical system.
– a preheat thermostat
The heater is designed to the heat exchanging principle
and operates intermittently, controlled by the
temperature control thermostat.
– a nozzle holder preheat cartridge
– a relay and wiring harness
The heaters DBW 2010, DBW 2020, DBW 300 and
Scholastic Heater™ basically consist of:
– the combustion air intake (adjustable)
– the combustion air fan and motor
– the fuel pump
– the fuel control valve and solenoid
– the nozzle holder and nozzle
– the ignition coil and ignition electrodes
– the combustion chamber
– the heat exchanger
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Webasto Thermo & Comfort N.A., Inc.
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. Overheat fuse (white wires)
23. Flame detector
7. Preheat thermostat (blue and
green wires)
16. Temperature control thermostat
(green and red wires)*
24. Fuel pump
8. Fuel control valve and solenoid
17. Temperature limiter
(green wires)
26. Combustion air intake with
adjusting shutter
9. Electrode holder
25. Fuel pipes
*Lower temperature version of the temperature control thermostat has white and orange wires.
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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. Overheat fuse (white wires)
23. Flame detector
7. Preheat thermostat (blue and
green wires)
16. Temperature control thermostat
(green and red wires)
24. Fuel pump
8. Fuel control valve and solenoid
17. Temperature limiter
(green wires)
26. Combustion air intake with
adjusting shutter
9. Electrode holder
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11
25. Fuel pipes
Webasto Thermo & Comfort N.A., Inc.
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.
ELECTRONIC CONTROL UNIT (1)
The control unit SG 1553 in 12 volt and 24 volt versions
is the central component to ensure controlled operation
and monitoring of combustion.
Temperature Limiter (green wires)
Switching temperature
– opens at 95° C (203° F)
Figure 3:
2.1.4
2.1.2
TEMPERATURE CONTROL THERMOSTAT (16)
After the operating temperature has been reached, the
temperature control thermostat opens and shuts off the
heating cycle and a purge cycle begins. Once the
operating temperature drops to the lower temperature
threshold of the control thermostat, the thermostat
closes and another heating cycle begins, thus,
maintaining a consistent coolant temperature.
Control unit
Figure 1:
Temperature Limiter
Control Unit
OVERHEAT FUSE (15)
Temperature Control Thermostat
The overheat fuse protects the heater from too high and
inadmissible temperatures. The overheat fuse contains a
fusible link that reacts when the temperature exceeds
138° C (280° F), and switches the heater off with a purge
cycle.
Version 1 (red and green wires)
– opens at 75 ± 3° C (167 ± 6° F)
– closes at 68 ± 5° C (154 ± 9° F)
Version 2 (orange and white wires)
– opens at 70 ± 3° C (158 ± 6° F)
– closes at 60 ± 5° C (140 ± 9° F)
Overheat Fuse (white wires)
Response temperature
138° C (280° F)
Figure 4:
Temperature Control Thermostat
NOTE: DBW 2020/300 Only. An optional
control thermostat could be mounted in the
heating system in place of the control
thermostat located on the heater.
Figure 2:
Overheat Fuse
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12
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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.
Figure 6:
Combustion Air Intake Bellows
IMPORTANT! The photo disc to which the flame
detector is attached must be flat and free floating
over the nozzle and electrodes.
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Webasto Thermo & Comfort N.A., Inc.
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.:
DBW 2010
4500 RPM
There are two different fan designs in use:
DBW 2020
5000 RPM
DBW 2010 — lateral canal fan
DBW 300
5800 RPM
DBW 2020/300 — radial fan
DBW 2010
Fan wheel
Drive motor
Cap
DBW 2020/300
Figure 7:
Combustion Air Fans
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14
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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. nozzle, the fuel
pressure should be set to 8 – 0.5 bar (116 – 7 psi).
Strainer
Figure 8:
Pressure
Regulation
Valve
Motor to Fan Coupling (Clutch)
NOTE: Before reusing the coupling, it has to
be checked for cracks, wear and the condition
of the flat portion of the center shaft hole. Too
much play on the shaft will result in a load
continuous noise.
Figure 10:
2.1.9
Fuel Pump Assembly
TOOTHED GEARING (6)
2.1.11 FUEL CONTROL VALVE AND SOLENOID (8)
The gears drive the fuel pump with a gear ratio of 1:3.5.
The fuel solenoid valve interrupts the fuel supply to the
atomizer nozzle when the heater is switched off and
during a control pause period. When there is no current
present, the solenoid valve is closed.
Plunger Valve
Figure 9:
Fuel Pump Drive Gearing
Figure 11:
NOTE: If signs of wear are showing within the
sector of the toothed gearing as well as at the
flat portion of the shaft hole of the large gear,
the gears will have to be replaced.
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15
Fuel Solenoid Assembly
Webasto Thermo & Comfort N.A., Inc.
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.
IMPORTANT! Never switch on the electronic
ignition unit without being connected to the
ignition electrodes!
Nozzle Holder
Nozzle
Figure 12:
Nozzle Holder and Nozzle
2.1.13 FUEL LINE CONNECTIONS (25)
+ Black Wire
Fuel lines from the fuel tank are connected to the suction
and return pipes of the heater in the case of the DBW
2010/2020/300.
– Brown Wire
Figure 14:
The Scholastic Series heater use a single fuel line that is
connected to the suction pipe of the heater. There is no
return fuel line on this model.
Electronic Ignition Unit
2.1.15 IGNITION ELECTRODES (13)
The ignition spark is formed between the points of the
ignition electrodes, thus starting the combustion process.
Dual Line System
(DBW 2010/2020/300)
Electrodes
Figure 15:
Setting Gauge
Ignition Electrodes and Setting Gauge
Single Line System
(Scholastic Heater)
Figure 13:
Fuel Pumps
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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.
DBW 2010
Preheat Thermostat
(blue and green wires)
Air
Swirler
Figure 16:
Switching temperature
– closes at 0° C (32° F)
– opens at 8° C (48° F)
DBW 2020/300
Figure 18:
Combustion Chambers
Preheat Thermostat
2.1.19 PRE-HEATER CARTRIDGE (10)
2.1.17 HEAT EXCHANGER (19)
The pre-heater is a heating element located in the fuel
nozzle holder. Operated by the preheat thermostat (7), it
heats the fuel inside the nozzle holder when the
temperature drops below 0° C (32° F).
The heat, produced by the combustion process, is
transferred to the coolant (water-antifreeze mixture)
flowing through the heat exchanger.
DBW 2010
Power consumption
130 Watts
Red - 12 V
Green - 24 V
Figure 19:
Heating Cartridge
DBW 2020/300
Figure 17:
Heat Exchangers
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Webasto Thermo & Comfort N.A., Inc.
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.
U 4810
The heaters may be operated with circulation pump U
4810 or U 4846 for the DBW 2010 heater, the U 4814,
or U 4851 for the DBW 2020 and 300 heaters and a
school bus specific, MP coolant pump for the Scholastic
Heater™.
U 4846
U 4814
U 4851
MP School Bus Pump
(Scholastic Heater)
Figure 20:
Webasto Thermo & Comfort N.A., Inc.
18
Coolant Circulating Pumps
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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. After
about 10 - 25 seconds, the solenoid valve (E) opens and
fuel is sprayed into the combustion chamber. At the
same time, the electronic ignition unit (D) produces high
voltage (8000V) and the fuel - air mixture in the
combustion chamber is ignited by the spark on the
ignition electrodes. The flame is detected by the flame
detector (F), then the electronic ignition unit stops
producing high voltage and combustion continues on its
own (spark on electrodes is required only to ignite the
flame). At this time the heater is working and produces
heat.
CONTROL IDLE PERIOD
3.2
Switching off the heater stops combustion. The
operating indicator light remains on and run-down
commences. The combustion air fan and circulation
pump are deactivated after approximately 150 seconds.
The operating indicator light goes out to indicate the
heater is now fully off.
A rise in temperature above the upper operating point
makes the solenoid valve in the fuel pump shut off the
fuel supply initiating the run-down. The flame
extinguishes, the combustion air fan and the circulation
pump however continue their operation. After
approximately 150 seconds run-down is completed with
deactivation of the combustion air fan.
The circulation pump remains in operation during the
control idle period. The operating indicator light also
remains on.
3.3
HEATING OPERATION
After reaching operating temperature the control unit in
conjunction with the temperature control thermostat
takes over to provide controlled operation by activation
and deactivation of the burner in order to maintain a
nearly constant temperature of the heat exchanger
(coolant).
Reactivation of the heater during run-down is permitted.
The burner immediately resumes operation after the runup time.
The heating operation is terminated as soon as the upper
operating point on the temperature control thermostat is
exceeded.
1
A. Green light: operation
indicator, control thermostat
B. Coolant circulation pump,
negative heater
C. Heater motor
D. Electronic ignition unit
E. Fuel solenoid valve
F. Flame detector
G. Control thermostat
3
2
4
2
5
3
6
7
A
B
C
D
E
F
G
10 - 25s 5 - 25s
8
~150s
9
10 - 25s 5 - 25s
10
8
1. Switch on
6. Switch off
2. Start
7. Heater stops
3. Combustion
8. Initial cycle
4. Control pause starts
9. Safety delay time
5. Control pause ends
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SWITCH OFF
19
9
~150s
10
10. Purge cycle
Webasto Thermo & Comfort N.A., Inc.
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. Any negative effect
caused by additives is not known. When the fuel for the
heater is drawn from the vehicle’s fuel tank, the vehicle
manufacturer’s specifications concerning additives are to
be observed. Any addition of waste oil is not permitted.
ELECTRICAL COMPONENTS
Control unit, fan and circulation pump motors, solenoid
valve, ignition coil, heater cartridge for nozzle block preheater and timer are designed either for 12-volt or 24volt operation. Temperature limiter, overheat fuse, flame
detector (photo eye), temperature control thermostat,
preheat thermostat and switches are voltage
independent components.
When changing to cold-resistant fuels, the heater must
be operated for approx. 10 minutes to ensure that the
fuel pump, nozzle holder, nozzle and lines are filled with
the new fuel.
When using fuel from a separate fuel tank and at
temperatures below 0° C, winter Diesel fuel must be
used.
NOTE: The allocation of circulation pumps to
heater units must be in accordance with coolant
resistances.
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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)
(0.7)
RATED VOLTAGE
V
12 or 24
OPERATING VOLTAGE
V
10-14 or
20-28
POWER CONSUMPTION OF HEATER
(WITHOUT COOLANT CIRCULATION PUMP)
60 Watts
PERMISSIBLE AMBIENT TEMPERATURE
DURING OPERATION OF HEATER, CONTROL
UNIT AND COOLANT CIRCULATION PUMP:
°C (°F)
+ 85 max. (+ 185 max.)
– 40... + 85 (– 40... + 185)
15
3.96
3.3
10
2.65
2.2
PERMISSIBLE OPERATING PRESSURE OF
THE COOLANT
bar (psi)
0.4-2.0 (6-29)
CO2 IN EXHAUST GASES% BY VOL.
10.5... 11.0
CO IN EXHAUST GASES% BY VOL.
0.2 max.
SMOKE NUMBER (BOSCH)
DIMENSIONS OF THE HEATER
INCL. CONTROL UNIT
mm (inch)
130 Watts
– 40... + 60 (– 40... + 140)
PERMISSIBLE STORAGE TEMPERATURE
CONTROL UNIT:
°C (°F)
HEATER, COOLANT CIRCULATION
PUMP:
°C (°F)
MIN. CAPACITY OF COOLING SYSTEM liter
(gal. – US)
(gal. – Imp.)
120 Watts
3.0 max.
L
W
H
WEIGHT OF HEATER INCL. CONTROL UNIT
kg (lb)
584 (23)
205 (8.1)
228 (9.0)
680 (26.7)
240 (9.5)
279 (11.0)
15 (33)
22 (48.5)
NOTE: Specifications for the Scholastic Heater are the same as the
DBW 2010 heater unless otherwise specified.
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Webasto Thermo & Comfort N.A., Inc.
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 0.4 bar
3406 - 4542
(15 - 20)
NOMINAL VOLTAGE
12 or 24
12 or 24
12 or 24
24
12
OPERATING VOLTAGE
10-14 or
20-28
10-14 or
20-28
10-14 or
20-28
20-28
10-14
POWER CONSUMPTION
DIMENSIONS
mm (inch)
WEIGHT
Watt
L
W
H
kg (lb)
RECOMMENDED FOR HEATER*
25
30
104
209
72
166 (6.5)
94 (3.7)
77 (3.0)
180 (7.0)
74 (2.9)
112 (4.4)
248 (9.76)
100 (3.9)
106 (4.17)
285 (11.22)
115 (4.53)
118 (4.64)
214 (8.42)
106 (4.16)
106 (4.16)
0.8 (1.8)
22 (48.5)
2.1 (4.6)
2.8 (6.17)
2.5 (5.5)
DBW 2010
DBW2010
DBW 2020
DBW 300
DBW 2020
DBW 300
Scholastic
Heater™
*Choice of circulating pump depends on resistance of coolant circuit.
4.3
PERMISSIBLE EXTENSION OF THE CONNECTIONS
DBW 2010
DBW 2020
DBW 300
Scholastic
Series
mm (inch)
m (ft)
m (ft)
6* (0.25)
10 (33)
2 (6.6)
6* (0.25)
10 (33)
2 (6.6)
6* (0.25)
10 (33)
2 (6.6)
6* (0.25)
10 (33)
2 (6.6)
COMBUSTION AIR INTAKE PIPE:
internal diameter
mm (inch)
maximum length
m (ft)
maximum degree of bends total
m (ft)
80 (3.2)
5 (16.5)
270°
80 (3.2)
5 (16.5)
270°
80 (3.2)
5 (16.5)
270°
80 (3.2)
5 (16.5)
270°
EXHAUST PIPE:
internal diameter
mm (inch)
38 (1.5)
5 (16.5)
270°
70 or 80**
(2.75 or 3.2**)
5 (16.5)
270°
38 (1.5)
m (ft)
m (ft)
70 or 80**
(2.75 or 3.2**)
5 (16.5)
270°
HOSE CONNECTIONS - INLET/OUTLET
outside diameter
mm (inch)
18 (0.75)
38 (1.5)
38 (1.5)
25 (1.0)
TEMPERATURE DIFFERENCE BETWEEN INLET
and OUTLET
°C (°F)
10 (18)
10 (18)
10 (18)
10 (18)
HEATER
FUEL LINE:
internal diameter
maximum length
suction head
maximum length
maximum degree of bends total
5 (16.5)
270°
*Other dimensions upon request.
**Heaters built until model number DBW 2020.31 and DBW 300.10 inclusively.
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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
5.2
Vol
tag
eS
upp
Ele
ctri
ly
cal
F
Ele
use
ctri
cal
Har
Ine
nes
rtia
s an
Sw
ON
itch
dC
onn
/O
FF S (Scho
ect
l
Ove
a
ion
wit
s
t
i
s
c
ch
rhe
or W Heat
a
t
Tem
Fus
er O
irin
e (W
per
nly
g
)
atu
Co
re L hite W
ntr
i
i
m
res
ol T
i
t
e
)
her
r (G
Flam
mo
ree
eD
sta
ete
t (G n Wir
Co
cto
es)
r
ntr
een
r (P
o
and
hot
I g n l Unit
o-c
Red
itio
ell)
nE
Wi
res
lect
Ign
)
rod
itio
es
nC
Ele
o il
ctri
–C
cM
oil
Wi
Fue
oto
res
r
l Su
ppl
y
Fue
l Pu
Fue mp
l So
Hig lenoid
hP
Val
res
ve
sur
Co
eN
ola
ozz
nt C
le
Co
ircu
mb
lati
ust
ng
ion
Exh
Pum
Air
aus
p
Inta
t Sy
Hea
ke
ste
m
ting
Sys
tem
CHECK, REPAIR OR REPLACE AS NECESSARY
No Function
OFF after 30 Seconds
Inoperative
No Prime Cycle
No After-run
Inoperative
Absent
Does Not Take Place
Stops After 30 Seconds
Cannot Be Stopped
Light Color Smoke
Dark Color Smoke
Overheating
TESTER INSTRUCTIONS
(TESTER P/N 1302691A)
2
1
The tester unit has been designed to quickly check the
proper operation of the various heater components. By
using the tester in place of the heater control unit, you
are able to manually control the heater to test
components and actually operate the unit in heating
mode.
3
TESTER 440280 for DBW 2010/2020/300 in 12 or 24 Volt
Appareil de Contrôle 440280 pour DBW 2010/2020/300 in 12 or 24 Volt
Control
Thermostat
(Aquastat)
+ –
Flame
Control
(Cellule
photoélectrique)
6
The actual testing is completed in two steps, first you
perform an individual component test and then a manual
start and run test, both designed to pinpoint actual
problems in the heater system.
5
On
(Ouvert)
4
On
(Ouvert)
7
The tester should be used in conjunction with this Service
and Repair Manual (P/N 699745) which details complete
troubleshooting and repair procedures.
Water Pump
(Pompe de
circulation)
Motor
(moteur)
Ignition Coil
(Centrale
d'allumage)
Solenoid Valve
(Aimant
d’électrovanne)
5.2.1
TEST PROCEDURES
SETUP:
1
2
3
4
5
6
7
LED – input power to heater
LED – control thermostat
LED – flame detector
On/Off switch – water pump
On/Off switch – motor
Push Button – ignition spark coil
Push Button – fuel solenoid valve
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A. Remove connector blocks from heater control unit,
inspect for loose wires, corrosion and proper wire
connections.
B. Plug control unit connector blocks into tester.
C. Set heater switch/timer to “ON” and turn vehicle
heater valve to “FULL” mode (if equipped).
D. Proceed to component test procedures.
23
Webasto Thermo & Comfort N.A., Inc.
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. 68 °C (155 °F) or lower
closed (heat required)
Push FUEL SOLENOID VALVE button (7) several clicking of solenoid should be
times
heard
- test temperature fuse (if equipped)
- test overheat limiter
- test solenoid valve
Push IGNITION SPARK COIL
button (6)
sparking should be heard
- check electrode gap
- test ignition spark coil
Turn MOTOR switch (5) “ON“
motor should run
- reset *inertia switch (Scholastic Heater Only)
- test motor
Turn WATER PUMP switch (4) “ON“
pump should run
- test pump
Table 1. Test procedures and result
* INERTIA SWITCH:
NOTE: Hold IGNITION SPARK COIL button (5)
ON until FLAME DETECTOR LED (3) lights or
combustion is heard, then release; in any case
do not hold button on for more than 15
seconds or damage to the coil may result.
All Scholastic heaters are equipped with a manual reset
inertia switch located on the tray floor near the coolant
pump. The switch has a round red diaphragm and about
the size of a 25 cent piece on top.
The purpose of this switch is to stop heater operation in
the event the vehicle is involved in an accident or receives
a strong impact shock, e.g. hitting a curb. When the
switch responds, the fan motor circuit is interrupted thus
stopping air and fuel delivery.
TEST RESULTS:
1. LED (3) lights and combustion achieved
–
2. Combustion achieved but no LED (3) light
Always check to make certain the inertia switch has not
been tripped. Resetting is accomplished by depressing
the red diaphragm on top of the switch. You should
hear an audible click whenever the switch is reset.
–
check flame detector
3. Combustion not achieved and no LED (3) light
MANUAL TEST RUN OF HEATER:
A. Turn the WATER PUMP switch (4) ON
B. Turn the MOTOR switch (5) ON
E.
C. Push and hold the FUEL SOLENOID VALVE button (7)
ON (starts fuel flow to combustion chamber)
D. Push and hold the IGNITION SPARK COIL button (6)
ON (starts electrodes sparking) until combustion has
taken place.
Webasto Thermo & Comfort N.A., Inc.
operation normal
24
–
check fuel nozzle
–
check fuel pressure
–
check for blocked fuel lines (dirt or ice)
–
check ignition electrodes for damage and set
gap
Heater should now be in heating mode and will
continue to run until you release the fuel solenoid
valve button (7) which stops fuel flow and
extinguishes the flame immediately.
Allow the heater to continue running for
approximately 30 seconds (cool down) after which,
turn the WATER PUMP switch (4) and the MOTOR
switch (5) OFF.
www.techwebasto.com
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. Replace the control unit
and retest the heater.
NOTE: Since the heater operates in the 68 °C
(155 °F) to 75 °C (167 °F) On to Off / Off to On
range, and the vehicle engine may be hot [e.g.
coolant above 75 °C (167 °F)], the heater will
not start until the coolant temperature is below
68 °C (155 °F). THIS IS NORMAL and does not
indicate a problem.
www.webasto.us
25
Webasto Thermo & Comfort N.A., Inc.
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
5.3.2
HEATER DOES NOT START WHEN SWITCHED ON
Voltage on terminal
B1, B2 and B4?
Are electric fuses
defective?
Volume on control
thermostat?
Volume on control
thermostat after
cooling of coolant
in the cycle?
Replace fuses and
switch heater ON;
does fuse release?
Feed connection
defective
Temperature in the
cooling cycle too high
Control thermostat
defective?
Are electric fuses
defective?
Voltage too low?
< 18 ± 1V resp.
< 9 ± 0.5V
Voltage on motor?
Under-voltage
protection in the
control unit has
reacted; charge battery
Voltage across
terminal C2 and C5
of control unit?
Control unit defective,
replace.
Check feed
connections to motor
for circuit interruptions
Is the motor easy to
spin up?
Is the motor easy to
spin up with the nozzle
holder plate removed?
Motor defective;
internal fault
Is the motor shaft easy
to spin up when
removed from
mounting?
Motor defective;
internal fault
Replace defective fan
shaft bearings / parts
Is the large spur gear
easily spun?
Fuel pump defective;
replace fuel pump
Motor defective;
internal fault
Webasto Thermo & Comfort N.A., Inc.
26
www.techwebasto.com
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.
Voltage across
terminal
C8 and C5?
Does flame
detector show
resistance >100 kΩ
when dark?
Check feed
connections of
control unit for
open or
interruption
Is there the same
effect with a new
ignition spark coil?
Remove intruption or
open in circuit
Ignition spark coil
defective
Insulator of
electrode defective
Flame detector
defective
Control unit defective
Is combustion
noise audible?
Is fuel splashing
out of the fuel
nozzle?
Does the fuel
solenoid valve
in the heater open?
Does fuel nozzle
produce good fuel
atomization?
Does flame
detector show
resistance >1.56 kΩ
under bright 50 Lux
light?
Flame detctor
defective, replace
www.webasto.us
Does the fuel
solenoid valve
in the heater open?
Volume on
solenoid valve?
Fuel solenoid valve
defective
Voltage on
solenoid valve?
Check feed
connections
Are ignition
electrodes correctly
set with gauge?
Adjust ignition
electrodes to
correct setting
with gauge
Does the pump
deliver fuel?
Fuel in the tank?
Refill fuel tank
Fuel nozzle is
blocked, replace
nozzle
Are all fuel lines
tightly connected?
Tighten lines, repair
leaks or replace
leaking gaskets
Is the gasket
surface of the fuel
valve piston or of
the air relief drill
hole dirty?
Remove fuel
pump; is the
shaft seal okay?
Clean or replace
Fuel suction line
blocked or fuel
waxing or water
in fuel freezing
or fuel tank vent
blocked
Check air intake
and exhaust outlet
for blockage. Clean
if necessary
Viscosity below
20 centiStokes?
Magnetic coil of
fuel solenoid valve
defective
27
Magnetic coil of
fuel solenoid valve
defective
Fuel nozzle is
blocked, replace?
Replace fuel
pump
Fuel quality or
grade not
appropriate for
cold weather
operation. Switch
to a winter grade.
Webasto Thermo & Comfort N.A., Inc.
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 5.3.7
Repair leakage points
Does the ignition spark
flash over on the high
voltage wire?
Does the ignition spark
flash over on the electrode
insulation?
High voltage wire defective
Ignition electrode(s)
defective
Possible leakage in fuel
suction or return fuel lines
Ignition spark coil defective
HEATER SWITCHES OFF BY ITSELF DURING OPERATION
Does the heater start after
repeated starting attempts?
Does heater reteact at all?
Fuel supply from tank has
been interrupted for an
extended period of time
Heater switches OFF after
approx. 30 sec. on fault;
continue fault finding
according to section 5.3.3
Webasto Thermo & Comfort N.A., Inc.
Continue fault finding
according to section 5.3.2
28
www.techwebasto.com
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.)
Has the air intake
bellows been
incorrectly set?
Are the permissible
combustion values
adjustable?
(see section 10.3)
Motor r.p.m. too low
Are there restrictions
or kinks in the fuel
return line?
Has the correct fuel
been used according
to the operating
instructions?
Observe the
recommendations
in the operating
instructions
Because of the return
fuel pressure, the flow
of the fuel nozzle is
too high
Check fuel pump
pressure; is the pump
pressure too high?
Is battery voltage,
when charged,
below 10 V
resp. 20 V
Adjust according
to instructions.
(see Sec. 6.2.5)
Charge battery
Gap distance between
the impeller and the
housing too great
(DBW 2010 and
Scholastic only)
Replace fuel nozzle
Does the heater
continue to smoke
after adjustment?
Motor r.p.m. too low
www.webasto.us
29
Webasto Thermo & Comfort N.A., Inc.
TROUBLESHOOTING
5.3.7
DBW 2010/2020/300 COOLANT HEATERS
HEATER SMOKES
NO
Does heater smoke more
than 20 seconds?
Are ignition electrodes
set correctly according
to setting gauge?
YES
Does heater smoke
after switching OFF?
Does heater smoke
during operation (also
in waves)?
Set ignition electrodes
correctly with setting
gauge
Fuel solenoid valve
piston is leaky
Replace fuel nozzle
Did other unsuccessful
start attempts precede?
Flow through fuel nozzle
insufficient, - replace;
does heater continue to
smoke?
Any accumulated fuel in
the combustion chamber
must be allowed to burn
off; Does heater
continue to smoke?
Replace fuel nozzle
Open burner, remove
combustion chamber;
are there coke deposits
visible in the combustion
chamber?
Clean combustion
chamber
5.3.8
HEATER CANNOT BE SWITCHED OFF
Is there current through
the switch or timer
when switched OFF?
Do exhaust gases still
emit from the exhaust
pipe after switching
OFF?
Electronic control unit
defective
Switch or timer defective
Webasto Thermo & Comfort N.A., Inc.
Does heater continue to
run more than 180 sec.
after switching OFF?
Does control thermostat
open when the upper
set point is reached?
Control thermostat
defective?
No positive voltage on
the fuel solenoid valve?
Electronic control unit
defective
Does fuel solenoid valve
close (stuck open)?
Solenoid valve defective
30
www.techwebasto.com
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.
To prevent fires do not switch heater on
with burner swung open.
6.2
ADJUSTMENTS
6.2.1
ADJUSTMENT OF CO2 CONTENTS
It is allowed to change the manufacturer’s setting for
combustion air quantity by rotation of the setting ring.
CO 2
–
+ CO 2
Measurement of the CO2 value of the exhaust gas must
be performed followed by an adjustment of the
combustion air quantity as required in case of:
– repairs to the burner head
Locking screw
– irregularities in combustion
– functional checks
– nozzle replacement
Figure 21:
6.2.1.1 SETTING PROCEDURE
Combustion Air / Fuel Mixture Adjustment
– Loosen locking screw (refer to Figure above) and
reposition shutter with locking screw until rated
value is obtained
13
– Tighten locking screw with 1.0 +0.5 Nm and apply
screw seal varnish to mark new position
12
11
NOTE: CO2 setting depends on fuel (viscosity)
and on geodetic altitude (0.1% per 100 m).
10
CO2 (Vol.-%)
9
8
If proper setting cannot be obtained, proceed as follows:
7
– Check burner head air side for damage and replace if
required
6
18
9
20
10
22
11
24
12
26
13
28
14
– Check fuel pump pressure and replace pump if
required
30
15
Voltage
CO2 - setting at 500 m above sea-level
– Check fuel filter and strainer in fuel pump for
contamination and replace if required
DBW 2010
(Nozzle: 0.35 gph)
DBW 2020
(Rev. ≥.33)
DBW 300
Fuel pump pressure set to 10 bar (145 psi)
www.webasto.us
– Adjust fuel pressure
– Replace fuel nozzle
– Measure burner motor speed
31
Webasto Thermo & Comfort N.A., Inc.
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. 23 may or will cause ignition failures.
In case of damage, cracked glass bulb or not obtaining
the rated values, replace the flame detector.
CHECK
NOTE: The ignition electrodes can be set with
the setting gauge as shown. In addition the
front edge of the setting gauge must rest
against the atomizer nozzle and the tips of the
electrodes in both notches.
– Swing burner head open (see Sec. 8.5.1)
– Disconnect flame detector leads
– Connect flame detector leads to ohm meter
– Cover flame detector glass bulb with your thumb
CHECK
– Check resistance (rated value: < 20 kOhm)
– Uncover flame detector and expose to strong light
– Swing burner head open (see Sec. 8.5.1)
– Check resistance (rated value: < 200 Ohm)
– Insulation body of the ignition electrodes for
damages
ALTERNATE METHOD USING TESTER (P/N 1302691A)
– Electrode spacing with setting gauge according to
Fig. 23.
– Exchange control unit with tester and swing burner
head open (see Sec. 8.5.1).
CAUTION: Do not touch the nozzle drilling
while measuring the electrode spacing.
Keep the electrode setting gauge clean and
free of contaminates.
– Watch “Flame Control” LED while holding your
thumb over the flame detector glass bulb. LED will
darken considerably.
– Remove your thumb, LED will brighten considerably.
(Shine a bright light on the flame detector if in a
dimly lit area.)
SETTING
– Place setting gauge over nozzle as shown.
– The fluctuation of the LED between dim and bright
will indicate the flame detector is working properly.
– Loosen clamp bolt until electrode can be moved with
slight effort
– If necessary, electrodes can be bent slightly to
conform to the setting gauge notches. Grip with
pliers at the bending point only.
– Once set, snug up clamp bolt and check electrode
spacing once again to confirm setting.
CAUTION: Do not over-tighten or bottom
out clamp bolt. Doing so will distort the
clamp causing the electrodes to spread
apart.
Screw
Disc
Window
If necessary,
grip here to bend
Flame Detector
Setting Gauge
P/N 310646
Millimeters
Figure 22:
Figure 23:
Flame Detector Check
Webasto Thermo & Comfort N.A., Inc.
32
4.5 ±
0.5
0.5
8 ± 0.5
5±
Setting of Ignition Electrodes
www.techwebasto.com
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. Doing so will cause damage to
the ignition coil.
FUEL PUMP CHECK
NOTE: The fuel pump and the fuel hoses must
be replaced every 5 years.
CHECK
CHECK
– Exchange control unit with tester and swing burner
head open (see Sec. 8.5.1).
NOTE: Take care when connecting DC voltage
to the ignition coil leads. Connect positive to
the black lead and negative to the brown lead.
– Remove nozzle.
– Screw pressure test gauge into nozzle holder.
– Swing burner head open (see Sec. 8.5.1)
– Switch on heater motor via tester.
– Supply DC voltage to coil leads. Positive to black
lead and negative to brown lead.
– Press fuel solenoid button on tester.
– Read pressure gauge. If adjustment is required,
release button and turn pump pressure screw 1/8 of
a turn at a time in or out to increase or decrease
pressure (see Fig. 10 for location of pressure screw).
– With ignition coil energized, an ignition spark will
jump the ignition electrodes.
ALTERNATE METHOD USING TESTER (P/N 1302691A)
– Exchange control unit with tester and swing burner
head open (see Sec. 8.5.1).
– Repeat testing and adjustment steps until pressure is
within specified range.
– Press and hold the ignition button to activate the
ignition coil and observe spark condition.
– Switch off heater switch on tester.
– Unscrew pressure test gauge.
CAUTION: Do not energize ignition coil for
a period longer than 15 seconds.
CAUTION: Do not damage nozzle bore.
– Screw in nozzle and torque to 20 Nm. (15 lb-ft)
DBW 2010 w/ 0.40 gph nozzle 8 –0.5 bar (116 –7 psi)
DBW 2010 w/ 0.35 gph nozzle 10 ±0.5 bar (145 ±7 psi)
DBW 2020 & DBW 300
10 ±0.5 bar (145 ±7 psi)
Nozzle Holder
Fuel Pump
Pressure Test Gauge
P/N 600190
+
+ Black Wire
120
– Brown Wire
80
160
0
220
40
Figure 24:
Ignition Coil Check
-
200
Gauge Face
Pressure
Regulator
Figure 25:
www.webasto.us
33
Fuel Pressure Check
Webasto Thermo & Comfort N.A., Inc.
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.
Short smoke emissions are normal caused by
clearing the area between the solenoid valve
and the nozzle bore.
Preheating is deactivated when the thermostat ambient
temperature is +8° C (46° F).
Power consumption is 130 ±13 Watts.
CHECK
CHECK
– Exchange control unit with tester P/N 1302691A and
swing burner head open (see Sec. 8.5.1).
– Swing burner head open (see Sec. 8.5.1)
– Press fuel solenoid button on tester several times.
You should hear an audible clicking sound indicating
that the fuel solenoid valve is functioning. If no
clicking can be heard, valve and or solenoid may
require replacement (see Sec. 9.2.6).
– Connect ohmmeter to connector
Webasto Thermo & Comfort N.A., Inc.
– Disconnect electrical connector
– Using cooling spray to cool down thermostat
– Resistance (max. 4.5 ).
34
www.techwebasto.com
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
RED
87
85
RED/YELLOW
BROWN
DS
BROWN
BLUE
K
L1
L2
M1
M2
P1
RED
RED
30
BROWN
RED
RED
BROWN
GREEN
BLACK
BLUE
HR
2
5
6
3
1
B
A
4
1
2
5
M2
BROWN
BLACK
BLACK
M
2
2
1
A
t°
1
4
1
2
5
B
6
S3
7
4
4
S4
BROWN
t°
5
3
6
WHITE
WHITE
M1
M
ORANGE
ORANGE
BATTERY
INDICATOR LIGHT
IGNITION ELECTRODES
FUSE 20A
FUSE 7.5A
FUSE 25A
HEATING ELEMENT
(fuel pre-heater)
RELAY (fuel pre-h eater)
SOLENOID VALVE
IGNITION COIL
COOLANT CIRCULATION PUMP
HEATER MOTOR
7-DAY TIMER (with adapter harness
configured for bus and coach use)
7-DAY TIMER (with adapter harness
configured for truck use)
FLAME DETECTOR
ON / OFF SWITCH (heater)
PREHEAT (FUEL) THERMOSTAT
(green and blue wires)
CONTROL THERMOSTAT
(white and orange wires)
TEMPERATURE LIMITER
(green and green wires)
BLUE
GREEN
35
GREEN
BT
DS
E
F1
F2
F3
HR
3
1
5
2
1
VIOLET
2
6
C
C
L1
3
7
4
8
VIOLET
www.webasto.us
BROWN
BLUE
BROWN
R
6
YELLOW
–
+
E
HEATER
L2
8
CONTROL UNIT
GREEN
Figure 26:
BLACK
7.1
BROWN
DBW 2010/2020/300 COOLANT HEATERS
CIRCUIT DIAGRAMS
7. CIRCUIT DIAGRAMS
DBW 2010 12 V AND 24 V - EARLY CANADIAN VERSION
Schematic - DBW 2010 Early Canadian Version
Webasto Thermo & Comfort N.A., Inc.
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)
TEMPERATURE LIMITER
(green and green wires)
9-PIN HARNESS CONNECTOR (round)
3-WAY INTERFA CE CONNECTOR
BROWN
BROWN
8
F1 F2 F3 F4
BROWN
RED
RED
RED
RED/YELLOW
RED/BLACK
GREEN
VIOLET
BROWN
WHITE
BLACK
30
87
K
HR
RED
RED
B
M
YELLOW
BROWN
BLUE
WHITE
M1
t°
85
86
S2
BLACK
BROWN
BROWN
GREEN
BROWN
BLUE
6
2
5
4
3
1
2
1
M2
5
B
A
M
2
2
1
A
t°
1
4
1
6
2
5
B
WHITE
S3
t°
5
7
3
6
4
4
S4
BROWN
WHITE
VIOLET
3
1
5
2
3
7
1
VIOLET
2
6
C
L1
C
4
8
BROWN
R
6
–
+
E
HEATER
L2
8
CONTROL UNIT
BLUE
BROWN
ORANGE
ORANGE
BLOWER
INTERFACE
OPTION
BLACK
BROWN
BLUE
GREEN
36
GREEN
X2
B
A
C
VIOLET
Webasto Thermo & Comfort N.A., Inc.
BROWN
GREEN
Figure 27:
YELLOW
7.2
BLACK
CIRCUIT DIAGRAMS
DBW 2010/2020/300 COOLANT HEATERS
DBW 2010 12 V AND 24 V - PRESENT NORTH AMERICAN VERSION
Schematic - DBW 2010 Present Version
www.techwebasto.com
BROWN
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
WHITE J
D
BROWN
RED
RED
BT
DS
E
F1
F2
F3
F4
F5
F6
K1
L1
L2
M1
M2
R
S1
BT
RED
F5
X1
E
F
BROWN
RED
GREEN
X2
ORANGE
2
M
1
K1
86
85
BROWN
M1
30
87
BROWN
GREEN
BLACK
GREEN
BROWN
BLACK
2
5
6
3
1
4
1
2
M2
5
B
A
BLACK
M
2
2
1
A
ORANGE
WHITE
RED
ORANGE
BLUE
RED
F6
t°
1
4
1
6
2
5
B
WHITE
S3
t°
5
7
3
6
4
4
S4
BROWN
RED
B A
ORANGE
GREEN
X3
3
1
5
WHITE
F1
2
1
3
7
C
4
8
L1
VIOLET
F4
2
6
C
BROWN
R
6
–
+
E
HEATER
L2
8
CONTROL UNIT
BLUE
F3 F2
BLUE
GREEN
37
GREEN
YELLOW
E F C D A B
VIOLET
www.webasto.us
BROWN
GREEN
Figure 28:
BLACK
7.3
BROWN
DBW 2010/2020/300 COOLANT HEATERS
CIRCUIT DIAGRAMS
DBW 2020 / 300 12 V AND 24 V - WITHOUT NOZZLE PREHEAT
Schematic - DBW 2020 / 300 Without Nozzle Preheat
Webasto Thermo & Comfort N.A., Inc.
BROWN
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) THERMOSTAT
(blue and blue wires)
CONTROL THERMOSTAT
(green and red wires)
TEMPERATURE LIMITER
(green and green wires)
9-PIN HARNESS CONNECTOR (round)
3-WAY CONNECTOR
2-WAY CONNECTOR
S1
DS
BROWN
RED
F5
GREEN
K2
86
85
BROWN
ORANGE
30
87
K1
2
t°
BROWN
X2
86
85
3
S2
1
30
87
WHITE
M1
HR
BROWN
GREEN
BLACK
GREEN
BROWN
BLACK
BROWN
WHITE
M
BLACK
WHITE
X1
E
F
2
5
6
3
1
4
1
2
M2
5
B
A
M
2
2
1
A
ORANGE
WHITE
RED
RED
ORANGE
BLUE
RED
F6
t°
1
4
1
6
2
5
B
WHITE
S3
t°
5
7
3
6
4
4
S4
BROWN
RED
B A
ORANGE
GREEN
X3
WHITE
BLUE
WHITE
BLUE
BLACK
BROWN
BLUE
GREEN
38
GREEN
F1
3
1
5
WHITE
F3 F2
2
1
3
7
C
4
8
L1
VIOLET
F4
2
6
C
VIOLET
Webasto Thermo & Comfort N.A., Inc.
BROWN
BROWN
R
6
–
+
E
HEATER
L2
8
CONTROL UNIT
GREEN
E F C D A B
BLUE
Figure 29:
YELLOW
7.4
BLACK
CIRCUIT DIAGRAMS
DBW 2010/2020/300 COOLANT HEATERS
DBW 2020 / 300 12 V AND 24 V - WITH NOZZLE PREHEAT
Schematic - DBW 2020 / 300 With Nozzle Preheat
www.techwebasto.com
BROWN
BROWN
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
(blue and blue wires)
CONTROL THERMOSTAT
(green and red wires)
TEMPERATURE LIMITER
(green and green wires)
9-PIN HARNESS CONNECTOR (round)
3-WAY CONNECTOR
DS
S1
BROWN
BROWN
RED
X2
2
1 3
BROWN
WHITE
GREEN
3
1
K2
86
85
87
BROWN
t°
30
BROWN
S2
HR
BROWN
GRAY
2
5
30
BLACK
4
GRAY
(Remote pump activation)
86
85
87
1
2
6
GREEN
ORANGE
BLACK
K1
BROWN
BLUE
GREEN
BLACK
RED
WHITE
BLUE
RED
M
WHITE
BLUE
RED
BROWN
WHITE
RED
BROWN
RED
BLACK
WHITE
I
M2
5
B
A
BLACK
2
1
A
2
M
BLACK
M1
t°
1
4
1
6
2
5
B
WHITE
S3
t°
5
7
3
6
4
4
S4
BROWN
RED
X1
E
F
ORANGE
GREEN
F5
3
1
5
WHITE
F1
BLUE
GREEN
39
BROWN
2
1
3
7
C
4
8
L1
VIOLET
F4
2
6
C
BROWN
R
6
–
+
E
HEATER
L2
8
CONTROL UNIT
GREEN
F3 F2
BLUE
RED
RED
ORANGE
BLUE
RED
E F C D A B
VIOLET
www.webasto.us
GREEN
YELLOW
Figure 30:
BLACK
7.5
BROWN
DBW 2010/2020/300 COOLANT HEATERS
CIRCUIT DIAGRAMS
SCHOLASTIC HEATER 12 V - WITH ON/OFF SWITCH
Schematic - Scholastic Heater™ With On/Off Switch
Webasto Thermo & Comfort N.A., Inc.
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 CABLE
TO THE HEATER
RED
X2
2
1 3
BROWN
WHITE
GREEN
3
1
K2
86
85
87
BROWN
t°
30
BROWN
S2
HR
BROWN
GRAY
2
5
30
BLACK
4
GRAY
(Remote pump activation)
86
85
87
1
2
6
BLACK
K1
BROWN
BLUE
GREEN
BLACK
RED
ORANGE
GREEN
COOLANT CIRCULATION PUMP
HEATER MOTOR
7-DAY TIMER MODEL 1529
FLAME DETECTOR
PREHEAT (FUEL) THERMOSTAT
(blue and blue wires)
CONTROL THERMOSTAT
(green and red wires)
TEMPERATURE LIMITER
(green and green wires)
HARNESS CONNECTOR (round)
3-WAY CONNECTOR
TIMER HARNESS CONNECTOR
TIMER CONNECTOR
DASH LAMPS
(OPTIONAL)
BLACK
RED
WHITE
GREEN
RED
VEHICLE
IGNITION +
BROWN
GRAY
GREEN
BLACK
BLUE
BROWN
BROWN
RED
M
WHITE
BLUE
7-DAY TIMER 1529
M1
WHITE
BLUE
RED
E F C D A B
BROWN
WHITE
RED
BLACK
WHITE
X1
E
F
BROWN
RED
I
M2
5
B
A
M
2
2
1
A
t°
1
4
1
6
2
5
B
WHITE
S3
t°
5
7
3
6
4
4
S4
BROWN
RED
F5
ORANGE
GREEN
BLACK
BLACK
BROWN
BLUE
GREEN
40
GREEN
RED
3
1
5
WHITE
F1
2
1
3
7
C
4
8
L1
VIOLET
F4
2
6
C
BROWN
R
6
–
+
E
HEATER
L2
8
CONTROL UNIT
BLUE
F3 F2
VIOLET
Webasto Thermo & Comfort N.A., Inc.
BROWN
YELLOW
Figure 31:
GREEN
7.6
BLACK
CIRCUIT DIAGRAMS
DBW 2010/2020/300 COOLANT HEATERS
SCHOLASTIC HEATER 12 V - WITH 7-DAY TIMER MODEL 1529
Schematic - Scholastic Heater™ With Digital 7-Day, 3 Program Timer Model 1529
www.techwebasto.com
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
GRAY
(Remote pump activation)
30
BLACK
GREEN
BLACK
RED
6
86
85
87
M
ORANGE
COOLANT CIRCULATION PUMP
HEATER MOTOR
7-DAY TIMER MODEL 1531
FLAME DETECTOR
PREHEAT (FUEL) THERMOSTAT
(blue and blue wires)
CONTROL THERMOSTAT
(green and red wires)
TEMPERATURE LIMITER
(green and green wires)
HARNESS CONNECTOR (round)
3-WAY CONNECTOR
TIMER HARNESS CONNECTOR
TIMER CONNECTOR
DASH LAMPS
(OPTIONAL)
VEHICLE
IGNITION +
BROWN
GRAY
GREEN
M1
M2
P2
R
S2
S4
RED
BLACK
BLACK
S3
BLUE
WIRING CABLE
TO THE HEATER
ORANGE
BLACK
WHITE
RED
RED
K1
GREEN
BLUE
BROWN
BROWN
RED
GREEN
BROWN
BROWN
RED
RED
GRAY
VIOLET
BROWN
8
10
X4
TO
TIMER
BT
WHITE
BLUE
7-DAY TIMER 1531
M1
WHITE
BLUE
RED
E F C D A B
BROWN
RED
BROWN
WHITE
I
M2
5
B
A
BLACK
2
1
A
2
M
BLACK
X1
E
F
BLACK
WHITE
t°
1
4
1
6
2
5
B
WHITE
S3
t°
5
7
3
6
4
4
S4
BROWN
RED
RED
ORANGE
GREEN
F5
3
1
5
WHITE
RED
2
1
3
7
C
4
8
L1
VIOLET
F4
2
6
C
BROWN
R
6
–
+
E
HEATER
L2
8
CONTROL UNIT
BLUE
F1
BLUE
GREEN
41
GREEN
YELLOW
F3 F2
VIOLET
www.webasto.us
BROWN
GREEN
Figure 32:
BLACK
7.7
BROWN
DBW 2010/2020/300 COOLANT HEATERS
CIRCUIT DIAGRAMS
SCHOLASTIC HEATER 12 V - WITH 7-DAY TIMER MODEL 1531
Schematic - Scholastic Heater™ With Digital 7-Day, 3 Program Timer Model 1531
Webasto Thermo & Comfort N.A., Inc.
CIRCUIT DIAGRAMS
7.8
DBW 2010/2020/300 COOLANT HEATERS
CONTROL UNIT - IDENTIFICATION OF TERMINALS
1
2
A
1
4
2
5
B
Figure 33:
1
5
3
6
2
6
4
7 8
C
Control Unit - Identification of Terminals
CONNECTOR BLOCK A
CONNECTOR BLOCK C
A1 (–) coolant circulating pump
A2 (+) coolant circulating pump
C1 (+) To temperature control thermostat*
C2 (+) To Blower motor
C4 (+) To overheat fuse, temperature limiter and
fuel solenoid valve
C5 (–) For all heater components
C6 (–) Flame detector
C7 (+) From normally closed control thermostat
C8 (+) To ignition coil
CONNECTOR BLOCK B
B1
B2
B3
B4
B5
B6
(+) On/Off switch with low voltage protection
(–) Battery negative
(+) Control light (Operation indicator)
(+) Battery positive
(+) Optional coolant pump control input
(–) Control light (Operation indicator)
* Control thermostat with white and orange wires.
Closes at 60 ± 5° C (140 ± 9° F)
Opens at 70 ± 3° C (158 ± 6° F)
* Control thermostat with red and green wires.
Closes at 68 ± 5° C (154 ± 9° F)
Opens at 75 ± 3° C (167 ± 6° F)
Webasto Thermo & Comfort N.A., Inc.
42
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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.
8.2
SERVICING
HEATER SERVICING
• at least once a year the heat exchanger must be
cleaned inside.
Maintenance of the heater is necessary for proper
operation and long life. Read and understand the
recommendations and procedures explained in this
manual before attempting to service or repair.
• in case of leakage the fuel pump and the fuel lines
must be replaced immediately, otherwise every 5
years.
If you wish to carry out extensive repair work on the
heater, it may be a good idea to remove it completely.
• the heater should be checked on regular intervals by a
Webasto service agent, the latest before the beginning
of the heating season.
The battery must not be disconnected while the heater is
running, otherwise the heater will overheat.
8.5.1
After working on the heating circuit replenish with a
coolant mix prepared with water and anti-freeze and
bleed circuit afterwards according to manufacturer’s
instructions.
8.3
BURNER HEAD OPENING AND CLOSING
WARNING: The ignition system operates
with high voltage. Prior to opening the
burner head the power source to the
heater has to be disconnected to prevent
lethal injuries.
After closing and fixing burner head,
reconnect connectors in the vehicle.
VEHICLE SERVICING
CAUTION: A temperature of 85 °C (185 °F)
must not be exceeded in the vicinity of the
heater in any circumstances (for example
when completing painting work on the
vehicle).
NOTE: Maintenance on the heater is easy. By
swinging the burner head open the following
components become accessible:
– fuel pump and fuel nozzle
If the vehicle requires electric welding, the heater must
be electrically disconnected from the vehicle (both “+”
and “–”).
– solenoid valve
– ignition electrodes
– flame detector (photo eye)
8.4
HEATER TEST RUN
– combustion chamber
– nozzle block pre-heater (if installed)
The heater must not be operated, not even with the
timer, in enclosed areas like garages or workshops not
equipped with exhaust ventilation facilities.
8.5
In order to obtain a convenient burner head opening
angle it may be required to disconnect the electrical
connections at the control unit.
MAINTENANCE
OPENING OR REMOVAL
1. Disconnect electrical connections at control unit if
required.
NOTE: The heater should be operated for
approximately 20 minutes every 4 weeks to
prevent mechanical parts seizing.
2. Loosen nuts (item 3, Fig. 34) enough to release
hinge bolts (2).
To ensure functional reliability of the heater the following
maintenance must be performed:
3. Swing hinge bolts (2) out of way.
4. Swing burner head (4) open.
• check combustion air inlet and exhaust outlet for
contamination and clean as required.
CLOSING OR INSTALLATION
• outside the heating season the heater should be
operated with the vehicle engine cold approximately
www.webasto.us
1. Swing burner head to the closed position.
2. Swing hinge bolts (2) to locking position.
43
Webasto Thermo & Comfort N.A., Inc.
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.
Figure 34:
Burner Head Attachment
Webasto Thermo & Comfort N.A., Inc.
44
www.techwebasto.com
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.
WARNING: In overheat condition the
heater outer shell may reach the flash point
temperature of Diesel fuel!
The cooling system coolant capacity must be at least 10
liters. The vehicle cooling system or the separate heating
circuit must use only pressure relief valves with an
opening pressure of at least 0.4 bar and of max. 2.0 bar.
• Protect lines from stone strikes and debris that could
damage them and result in leakage.
• Dripping or evaporating fuel must not be
allowed to accumulate or ignite on hot
components or electrical equipment.
It is a basic requirement to use the coolant hoses supplied
by Webasto, otherwise the hoses must at least meet the
specifications of DIN 73411. The hoses have to be
installed free of kinks and for proper venting in an
inclination. Hose connections must be secured against
slippage with hose clamps.
The installation of an additional fuel pump is not
allowed.
Fuel lines permissible dimensions:
• Inner diameter for suction and return line: 6 mm
(except Scholastic Heater™).
NOTE: The specified tightening torques of the
hose clamps used must be complied with.
• Scholastic Heater™ inner diameter for suction line:
3/16 inches.
• Maximum permissible length for each suction and
return line: 10 m
Prior to the heater’s first operation or after replacement
of the coolant, attention must be paid to carefully bleed
the cooling system. Heater and lines must be installed so
that static venting is guaranteed.
• Maximum permissible suction height: 2 m
• Maximum permissible priming pressure: 0.3 bar for
suction and return line.
Improper venting may cause malfunctions by overheating
in equipment operation.
8.6.2.2 FUEL FILTER
Proper venting may be identified by a circulation pump
almost noiseless in operation.
A fuel filter supplied as deliverable item or cleared for use
8.6.2
Installation position possibly vertical with horizontal
direction of flow. To avoid operating malfunctions
replace filter or filter cartridge once a year or more often
if fuel is contaminated.
by Webasto is to be fitted.
CONNECTION TO VEHICLE FUEL SYSTEM
Fuel is tapped from the fuel reservoir of the vehicle or
from a separate fuel tank.
8.6.2.1 FUEL LINES
8.6.3
In order to avoid air from being captured in fuel lines,
they should only be installed with an incline. The fuel
line joints are to be secured against slipping with hose
clamps should no screwed mechanical unions be in use.
CAUTION: Observe official regulations
concerning the installation (see 1.6).
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.
Should fuel hoses be installed always use the hoses
supplied or offered by Webasto. If other hoses are used
they must at least meet the specifications of DIN733791C; type 3. Fuel hoses must not be kinked or twisted
and must be secured with clamps every 25 cm (10 in.).
It must be located so that no clogging by contamination,
impact of snow, or intake of splash water is to be
expected.
Also, fuel lines may be used consisting of materials
standard in the manufacturing of vehicles, e.g. steel or
plastic lines made of unhardened, light and temperature
stabilized PA11 or PA12 (e.g. Mecanyl RWTL) according
www.webasto.us
COMBUSTION AIR SUPPLY
The combustion air intake and exhaust outlet is to be
located so that no air pressure difference builds up in any
operating condition of the vehicle.
45
Webasto Thermo & Comfort N.A., Inc.
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.
– replacement of overheat fuse
If the heater is located in a closed installation box, a vent
port is required:
– replacement of nozzle preheat cartridge
• DBW 2010: 20 cm2 (3.1 inch2)
– replacement of ignition coil
• DBW 2020/300: 30 cm2 (4.65 inch2)
– replacement of flame detector
– replacement of temperature control thermostat
– replacement of burner
– replacement of fuel atomizing nozzle
– replacement of nozzle preheat thermostat
– replacement of combustion chamber
If the temperature in the installation box exceeds the
permitted ambient temperature of the heater (see
Technical Data), the vent port must be enlarged.
– replacement of control unit
8.7.1
8.6.4
HEATER, REMOVAL AND INSTALLATION
EXHAUST LINE
8.7.1.1 REMOVAL
CAUTION: Observe official regulations
concerning the installation (see 1.6).
1. Disconnect connectors of cable harness in vehicle
and of circulation pump.
The exhaust pipe outlet opening must not point in the
direction of motion.
2. Disconnect combustion air intake on heater if
equipped.
The exhaust pipe outlet opening must be located so as
not to expect clogging by snow or mud.
3. Loosen clamp on exhaust outlet.
4. Loosen fuel supply and return line connections and
fit dummy plugs. Close water valves as applicable.
The combustion air intake and exhaust outlet is to be
located so that no air pressure difference builds up in any
operating condition of the vehicle.
5. Loosen hose clamps on coolant hoses, disconnect
hoses and fit dummy plugs.
6. Remove 3 screws and washers or 4 screws and
washers of heater base.
Rigid pipes made of unalloyed or alloyed steel with a
minimum wall thickness of 1.0 mm have to be used as
exhaust line or flexible pipes made of alloyed steel only.
7. Remove heater.
The exhaust pipe is secured to the air heater e.g. with a
clamp.
8.7.1.2 INSTALLATION
– Permissible exhaust line dimensions:
1. Locate heater for installation and secure with 3
screws and washers or 4 screws and washers.
DBW 2010 = 38 mm (1.5 in.)
2. Secure line on exhaust outlet using clamp.
DBW 2020 up to .32 / DBW 300 up to .15 = 80 mm
(3.15 in.)
3. Slide on coolant hoses and fasten with hose clamps.
Torque clamps with 1.5 Nm. Open water valves.
DBW 2020 from .33 / DBW 300 from .165 = 70 mm
(2.75 in.)
4. Connect fuel supply and return lines and tighten
connections or screw tight with banjo bolt and new
gaskets.
– max. length: 5 m (16 ft)
– max. bend: 270°
5. Secure combustion air inlet line on heater if
applicable.
As an alternative an exhaust deflector can be installed
when cleared by Webasto.
8.7
6. Connect electrical connectors of cable harness in
vehicle and to circulation pump.
REMOVAL AND INSTALLATION
7. Bleed fuel supply system.
CAUTION: In installed condition only the
following disassembly or removal
procedures are permitted should enough
space for removal allow such action:
Webasto Thermo & Comfort N.A., Inc.
8. Bleed coolant circuit.
46
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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
8.7.3
NOTE: The replacement procedure for the
combustion chamber is identical with the heater
installed or removed.
Perform replacement in accordance with
9.2.17.
WARNING: The heater operates on high
voltage. Prior to replacement of
combustion chamber, disconnect electrical
connectors of cable harness in vehicle to
avoid lethal accidents.
OVERHEAT FUSE, REPLACEMENT
NOTE: The replacement procedure for the
overheat fuse is identical with the heater
installed or removed.
Perform replacement in accordance with 9.2.1.
8.8
8.7.5
After heater installation the coolant circuit and the fuel
supply system must be thoroughly bled observing the
vehicle manufacturer’s instructions. During test runs all
coolant and fuel line connections have to be checked for
security and no leakage. Should the heater in operation
enter a fault condition, perform troubleshooting (refer to
Section 5).
WARNING: The ignition system operates
on high voltage. Prior to replacement of
burner, disconnect electrical connectors of
cable harness in vehicle to avoid lethal
accidents.
8.8.1
IGNITION COIL, REPLACEMENT
Set vehicles own heating system to "warm" and
replenish coolant which must consist of at least 20%
anti-freeze (glycol base for protection against corrosion).
When using pure water there will be no protection
against corrosion and due to the lower boiling point of
the water when overheating loss of cooling water may
result requiring continuous replenishment. Additives in
the coolant must not affect metals, plastics or rubber and
leave no deposits.
WARNING: The ignition system operates
on high voltage. Prior to replacement of
the ignition coil and related components,
disconnect electrical connectors of cable
harness in vehicle to avoid lethal accidents.
Then operate engine at increased idle until radiator
thermostat opens. Shut down engine, check coolant level
and replenish as required.
FLAME DETECTOR (PHOTO EYE), REPLACEMENT
Switch on heater and vehicle heating fan with engine
shut down. After a certain cool-down period the heater
must automatically switch on and control to off. In case
of no restart attempt the temperature limiter on the
NOTE: The replacement procedure for the
flame detector is identical with the heater
installed or removed.
Perform replacement in accordance with 9.2.9.
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WATER CIRCUIT, BLEEDING
NOTE: Bleeding must always be performed in
accordance with manufacturer’s instructions.
For bleeding the circulation pump must not be
switched on.
NOTE: The replacement procedure for the
ignition coil is identical with the heater installed
or removed.
Perform replacement in accordance with
9.2.11.
8.7.7
FIRST OPERATION
BURNER HEAD, REPLACEMENT
NOTE: The replacement procedure for the
burner head is identical with the heater installed
or removed.
Perform replacement in accordance with 9.2.5.
8.7.6
COMBUSTION CHAMBER, REPLACEMENT
TEMPERATURE THERMOSTAT, REPLACEMENT
NOTE: The replacement procedure for the
temperature control thermostat is identical with
the heater installed or removed.
Perform replacement in accordance with 9.2.2.
8.7.4
SERVICING
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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.
NOTE: The heater may be equipped with an
automatically resetting temperature limiter. The
manual reset is not necessary.
Webasto Thermo & Comfort N.A., Inc.
FUEL SUPPLY SYSTEM, BLEEDING
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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.
• Check terminals for corrosion and contacts for
security. Repair as required.
For re-assembly only components of the proper service
part kits are to be used.
9.1.1.2 COMBUSTION CHAMBER, VISUAL INSPECTION
WARNING: The ignition system operates
on high voltage. Prior to replacement
disconnect connectors of cable harness in
vehicle to avoid lethal accidents.
– Check swirl ring for security.
– Check swirl ring for melting and deformation (DBW
2010).
– Inspect combustion chamber for oxidizing and coke
deposits and remove as required.
The following components may also be replaced with the
heater installed unless restricted space prevents access:
– Check welding seem for cracks.
– replacement of temperature limiter
NOTE: Longitudinal cracks up to 38 mm (1.5
in.) are allowed.
– replacement of temperature control thermostat
– replacement of overheat fuse
9.1.1.3 HEAT EXCHANGER, VISUAL INSPECTION
– replacement of burner
– Inspect exhaust ducting in heat exchanger for
sooting, deposits, damage and corrosion.
– replacement of fuel atomizing nozzle
– replacement of nozzle preheat cartridge
– replacement of nozzle preheat thermostat
NOTE: Deposits are to be removed with water
jet and brush.
– replacement of ignition coil
– replacement of flame detector
– replacement of combustion chamber
– Inspect heat exchanger for exterior damage,
deformation, etc.
– replacement of control unit
9.1.1
WORK ON COMPONENTS AFTER DISASSEMBLY
NOTE: Heavy deformation may cause
restricted flow of coolant.
CAUTION: All gaskets located between
disassembled components must always be
discarded and replaced with new gaskets.
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CAUTION: When replacing the combustion
chamber on heaters installed vertically,
remove deposits in heat exchanger using a
suitable tool.
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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. Turn counterclockwise to remove overheat fuse
(item1, Fig. 36) from dry-well.
9.2.1.2 INSTALLATION
1. Turn overheat fuse clockwise into dry-well until
snug but not tight.
DBW 2010
2. Turn out 1/2 turn.
3. Plug connector into connector block.
NOTE: Observe electrical wiring color coding
when making connections.
Hexagon nut
9.2.2
TEMPERATURE CONTROL THERMOSTAT,
REPLACEMENT
9.2.2.1 REMOVAL
0.15 ± 0.05 mm
(.006 ± .002 inch)
1. Disconnect electrical connection to temperature
control thermostat at connector block.
2. Turn counterclockwise to remove temperature
control thermostat (item 2, Fig. 36).
Figure 35:
9.2.2.2 INSTALLATION
Clearance Adjustment - DBW 2010 Fan
1. Turn temperature control thermostat clockwise into
bracket until snug.
DBW 2020/300 ONLY:
– The hub of the impeller has to be checked for cracks
and the cover disc (back wall) as to its stability.
Webasto Thermo & Comfort N.A., Inc.
2. Plug connector into connector block.
Observe electrical wiring color coding when
making connections.
50
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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. Turn temperature limiter clockwise into bracket until
snug.
1. Carefully push control unit (into holding clip or slide
into position with clip attached (Fig. 37).
2. Plug connector into connector block.
2. Restore electrical connections.
NOTE: Observe electrical wiring color coding
when making connections.
9.2.5
BURNER, REPLACEMENT
9.2.5.1 REMOVAL
1. Disconnect electrical connections on burner and
loosen fuel lines.
2. Loosen two nuts (item 3, Fig. 38) until hinge bolts
are free.
3. Swing hinge bolts (2) open and remove cotter pin
(1).
4. Remove burner (4).
2
1
9.2.5.2 INSTALLATION
1. Position burner (4, Fig. 38) for installation, swing
hinge bolts (2) closed and secure temporarily using
hinge bolts (2).
3
2. Insert cotter pin (1) according to the intended
opening swing direction.
3. Tighten nuts:
DBW 2010 = 5 - 6 Nm (44 - 53 lb-in.).
DBW 2020/300 = 7.5 - 8.5 Nm (66 - 75 lb-in.).
4. Connect fuel lines.
5. Restore electrical connections.
1 Overheat Fuse
2 Temperature Control Thermostat
3 Temperature Limiter
Figure 36:
Temperature Control Elements
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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
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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. Loosen the retaining clamp bolt and dismount the
ignition electrodes.
4. Remove disc retaining ring and disc. Allow the disc
to hang from the electrical leads.
4. Remove disc retaining ring and disc.
5. Disconnect the electrical leads from the fuel
solenoid.
NOTE: During the following steps, ensure that
escaping fuel is captured or immediately
neutralized and properly disposed of.
6. Unscrew the lock-nut (item 1, Fig. 39) securing the
solenoid to the valve chamber (4) and slide
magnetic head (3) back.
5. Disconnect the fuel return and supply pipes from
the fuel pump.
7. Unscrew valve chamber (4) from nozzle holder (9).
6. Disconnect the fuel delivery pipe from the pump to
the nozzle holder.
9.2.6.2 INSTALLATION
1. Unscrew lock-nut (item 1, Fig. 39) from new valve
assembly.
7. Unscrew the four screws on the back wall and take
the complete assembly out.
2. Make sure new O-ring seal (5) is in place on valve
chamber (4) and items 6, 7 and 8 are present and
correctly oriented inside the valve chamber.
8. Remove the retaining ring from the fuel pump shaft
and dismount the gear-wheel.
9. Remove the two bolts securing the fuel pump to the
back wall.
3. Screw assembled valve into nozzle holder and
torque to 11.5 Nm (8.5 lb-ft).
9.2.7.2 INSTALLATION
4. Slide the magnetic head (3) into place making sure
the boss registers in the end plate recess.
NOTE: Do not disturb the pump pressure
regulating screw. The pump has been pre-set to
the correct pressure.
5. Secure with the lock-nut (1) and washer (2).
6. Install the round disc and retaining ring.
7. Connect electrical leads to fuel solenoid.
1. Attach new fuel pump to back wall with the two
screws removed earlier.
8. Install and adjust ignition electrodes (see Sec. 6.2.3).
9. Install burner head (see Sec. 9.2.5).
1
2. Install gear-wheel on pump shaft and secure with
retaining ring.
3. Dot gear-wheel in four places with ISOFLEX LDS 18
Special A lubricant P/N 143820 (45 gram tube).
2
3
4. Insert assembly into burner head being careful to
mesh gears and secure with the four bolts removed
earlier.
4
5
5. Connect fuel pipes.
6
7
6. Install disc with flame detector and retain with ring.
8
7. Install and adjust ignition electrodes (see Sec. 6.2.3).
9
1
2
3
4
5
Lock-nut
Washer
Magnetic Head
Valve Chamber
O-ring
Figure 39:
8. Install burner head (see Sec. 9.2.5).
6
7
8
9
Stepped Roll Pin
Spring
Plunger
Nozzle Holder
Fuel Valve and Solenoid Assembly
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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. Position flame detector in slot of disc and secure
with screw and lock washer.
FUEL NOZZLE, REPLACEMENT
3. Tighten screw to 5 Nm - 6 Nm (44 - 53 lb-in.).
9.2.8.1 REMOVAL
4. Swing burner head closed (see Sec. 8.5.1).
1. Swing burner head open (see Sec. 8.5.1).
2. Unscrew and remove nozzle using a nozzle wrench
or two wrenches (16 mm & 19 mm).
NOTE: Ensure cleanliness is maintained when
installing the nozzle. Only touch the nozzle at
its hexagon surface. The fuel nozzle should be
replaced annually.
Screw
Disc
NOTE: If ignition electrodes are disturbed
during nozzle replacement, they will require
adjustment (see Sec. 6.2.3).
Window
Flame Detector
9.2.8.2 INSTALLATION
1. Screw in new high pressure nozzle and tighten to
20 Nm (15 lb-ft.).
2. Swing burner head closed (see Sec. 8.5.1).
Figure 42:
Webasto Thermo & Comfort N.A., Inc.
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Flame Detector Replacement
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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. Disconnect the ignition leads from the ignition
electrodes.
3. Remove the four screws securing the ignition coil to
the protection cap (see Fig. 44).
9.2.10.2 INSTALLATION
1. Install the new ignition electrodes.
4. Lift coil off cap enough to access electrical
connectors and disconnect.
2. Connect the ignition leads to the electrodes.
3. Adjust ignition electrodes (see Sec. 6.2.3).
9.2.11.2 INSTALLATION
4. Swing burner head closed (see Sec. 8.5.1).
1. Press electrical connectors together.
Brown – Brown
Black – Yellow
2. Place ignition coil into position making sure not to
jam or trap electrical cables.
3. Secure ignition coil with four screws removed
earlier.
4. Plug ignition leads onto ignition electrodes making
sure to fully engage into their niches
5. Check electrode gap with gauge and adjust if
necessary (see Sec. 6.2.3).
6. Swing burner head closed (see Sec. 9.2.5).
Figure 43:
Ignition Electrode Replacement
+ Black Wire
– Brown Wire
Figure 44:
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Ignition Coil Replacement
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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. Align motor shaft, coupler (4) and flange (3) with
housing (5) and attach with screws (7).
2. Remove four screws (item 6, Fig. 45) and withdraw
protection cap (1) from burner.
4. Tighten screws (7) to 5 - 6 Nm (44 - 53 lb-in.).
3. Disconnect motor leads.
5. Connect motor electrical leads.
4. Remove three screws (7) with lock washers and
withdraw drive motor (2).
6. Locate protection cap (1) and secure with the four
screws (6) removed earlier.
5. Remove two screws (8) from motor (2) and flange
(3).
7. Tighten screws (6) to 2 Nm (18 lb-in.).
8. Install ignition coil
6. Inspect all parts for wear and damage and replace
as necessary.
DBW 2010
9
8
7
6
5
4
3
2
9
8
1
7
6
5
4
3
2
1
Figure 45:
DBW 2020/300
Drive Motor Assembly
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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).
9.2.13.1 REMOVAL
4. Adjust fan clearance according to instructions in
Sec. 9.1.1.4.
1. Swing open or remove burner head (see Sec. 9.2.5)
2. Move ignition coil out of the way. Refer to Sec.
9.2.11 for guidance.
DBW 2020/300 ONLY
3. Remove four screws (item 6, Fig. 45) and withdraw
protection cap (1) from burner.
5. Assemble fan, shaft, bearings and drive gear
components if required (see Sec. 9.2.16).
4. Disconnect motor leads.
5. Remove drive motor (see Sec. 9.2.12).
6. Make sure O-ring (item 10, Fig. 48) in bearing recess
of housing (item 5, Fig. 46) is present and in place.
6. Remove four Allen Socket screws (item 1, Fig. 46 )
and washers (2) from motor carrier (3).
7. Push fan assembly into housing (5) until motor
carrier (3) is fully seated.
7. Remove four screws (10) from nozzle holder plate
(9) and pull plate free.
DBW 2010/2020/300
8. Install motor carrier (item 3, Fig. 46 ) over fan (4).
DBW 2010 ONLY:
9. Install and tighten screws to
– DBW 2010 - 5.5 - 6.5 Nm (48.5 - 57.5 lb-in).
– DBW 2020/300 - 8.0 Nm ± 10% (71 lb-in ± 10%).
8. Remove lock-nut (8), drive gear (7) and washer (6).
9. With a hammer and small drift, tap fan shaft and
fan (4) free from housing (5)
10. Install drive motor (see Sec. 9.2.12).
11. Connect electrical leads.
10. Perform further disassembly of shaft, bearings and
gears if necessary (see Sec. 9.2.15).
12. Install protection cap and secure with four screws
(item 6, Fig. 45) removed earlier.
DBW 2020/300 ONLY
13. Install ignition coil. Refer to Sec. 9.2.11 for
guidance.
11. Grasp motor carrier (item 3, Fig. 46 ) and with a
slight rocking motion, work the motor carrier and
fan (with bearing), free from housing (5).
12. Perform further disassembly of shaft, bearings and
gears if necessary (see Sec. 9.2.16).
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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
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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.
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
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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).
NOTE: The DBW 2010 burner tube may
require careful prying around the parameter of
the tube to release it from the heat exchanger
(see Fig. 49).
4. Withdraw combustion chamber from heat
exchanger.
5. Remove heat exchanger.
6. Perform procedures on components after
disassembly (see Sec. 9.1.1).
NOTE: It is important that the heat exchanger
and combustion chamber are cleaned and
inspected periodically and at least annually.
9.2.18.2 INSTALLATION
DBW 2010 burner tube
removal. Carefully pry
out with screw driver.
Figure 49:
1. Slide combustion chamber fully into heat exchanger.
2. Install burner head (see Sec. 9.2.5).
3. Attach cables to heat exchanger
DBW 2010 Burner tube removal
4. Install and connect temperature control thermostat,
temperature limiter and overheat fuse.
3. Perform procedures on components after
disassembly (see Sec. 9.1.1).
NOTE: DBW 2010 Only: In case the
combustion air swirler has been damaged,
distorted or melted by high heat of a burn-back
condition, the complete combustion chamber
and the flame detector must be replaced.
DBW 2010
9.2.17.2 INSTALLATION
1. Slide combustion chamber fully into the heat
exchanger.
2. Swing burner head closed (see Sec. 8.5.1).
DBW 2010
DBW 2020/300
Figure 51:
DBW 2020/300
Figure 50:
Heat exchanger replacement
Burner tube replacement
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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. Connect the electrical leads and seal connector with
dielectric grease such as Permatex® Dielectric Tuneup Grease or 3M™ Silicone Paste (Dielectric
Grease).
1. Drain the coolant. Alternatively, the hoses leading
to the pump can be pinched closed with hose
clamping pliers.
3. Disconnect coolant hoses from pump.
5. Refill coolant system and bleed trapped air out of
the coolant circuit according to instructions in
Sec.8.8.1.
4. Dismount coolant pump.
6. Switch on and check function and for any leakage.
2. Disconnect the circulation pump electrical leads.
9.3.2
DISASSEMBLING
1. Clean the exterior of the pump and hold pump in a
soft-jaw vice.
U 4810
2. Unscrew the impeller housing screws and remove
housing and O-ring.
3. Unscrew the impeller nut and carefully pry off
impeller with two screwdrivers.
4. Remove the spring seal, ceramic and rubber seals.
18
5. On the U4810 pump, unscrew the pump base
screws and remove the base and the O-ring.
9
18
10
6. Inspect all parts and replace if necessary. Seals are
always replaced.
9.3.3
12
11
ASSEMBLING
8
1. Connect pump motor to a power source. With a
strip of very fine emery cloth, polish the pump shaft
to remove any contamination.
6
7
5
4
2. Remove power source from pump motor.
3
3. Assemble pump with all parts in order as shown in
Fig. 53 through Fig. 55. The ceramic seal and the
spring seal must be fitted as shown in Fig. 52 with
the hard side of the spring seal (B) against the
ceramic seal face (A).
2
1
1
2
3
4
5
6
A
Screw - Impeller Housing
Impeller Housing
Nut - Impeller
Impeller
Spring Seal
Stationary Ceramic Seal
Figure 53:
7
8
9
10
11
12
Rubber Seal
O-ring
Screw - Pump Base
Washer - Pump Base
Pump Base
Rubber Shaft Seal
U4810 Circulation Pump - Exploded View
B
Figure 52:
Seal Orientation
Webasto Thermo & Comfort N.A., Inc.
62
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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 leak or replace). The
driven magnet of the pump must be free of metallic
contaminates otherwise the heater may overheat
due to loss of coolant circulation. The heater’s
overheat protection is likely to respond.
4
20
20
3
2
1
1
2
3
4
O-ring - Impeller Housing
O-ring - Magnetic Drive
Impeller Housing
Screw - Impeller Housing
Figure 55:
www.webasto.us
63
U4846 Circulation Pump - Exploded View
Webasto Thermo & Comfort N.A., Inc.
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. Disconnect the circulation pump electrical leads.
3. Disconnect coolant hoses from pump.
9.4.4
4. Dismount coolant pump.
INSTALLING
1. Mount the pump.
9.4.2
DISASSEMBLING
2. Connect coolant hoses to pump and tighten hose
clamps.
1. Clean the exterior of the pump and hold pump in a
soft-jaw vice.
3. Remove hose clamping pliers if used.
2. Unscrew the impeller housing screws and remove
housing and O-ring.
4. Connect the electrical leads and seal connector with
dielectric grease such as Permatex® Dielectric Tuneup Grease or 3M™ Silicone Paste (Dielectric
Grease).
3. Unscrew the impeller lock screw and remove
impeller.
5. Refill coolant system and bleed trapped air out of
the coolant circuit according to instructions in
Sec.8.8.1.
4. Remove the seal assembly.
5. Remove the pump adapter (base).
6. Inspect all parts and replace if necessary. Seals are
always replaced.
6. Switch on and check function and for any leakage.
8
7
6
5
4
3
2
1
1
2
3
4
Figure 56:
Impeller Housing
O-ring
Impeller
Spring Seal Assembly
5
6
7
8
Pump Base
Screw - Impeller Housing
Nut - Pump Base
Motor
MP School Bus Circ. Pump - Exploded View
Webasto Thermo & Comfort N.A., Inc.
64
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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
10.2 TESTER
Used for testing components of the heater, test running
the heater, making fuel pressure adjustments when used
with a pressure gauge and general troubleshooting.
Tester is connected in place of the control unit.
Tester Part Number 1302691A
An optional 5 ft. extension harness (P/N 905491A) is
available for tester where additional reach is required.
10.4 SMOKE NUMBER TEST APPARATUS
Used for checking smoke number
TES
T
Ap ER 4
pare 40
il d 280
e C for
on
D
trô BW
le 4 20
40 10/2
28
0 p 020/3
ou
r D 00 in
BW
1
20 2 or
10
/20 24 Vo
Co
20
/30 lt
Thentrol
0 in
(Aq rmo
O
12
(Ou n
uas stat
or
vert
tat)
24
Fla
)
Vo
lt
Come
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(Ou
(Centrol
vert
ll
ph ule
)
oto
éle
ctr
iqu
e)
+
Wa
(Po ter P
circmpe ump
ula de
tio
n)
–
Mo
(m tor
ote
ur)
Ign
(Ceition
d'a ntraleCoil
llum
age
)
Sole
(Aimnoid
d’é ant Valv
e
lec
tro
van
ne)
www.webasto.us
65
Webasto Thermo & Comfort N.A., Inc.
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
10.6 FUEL PRESSURE GAUGE
Used for checking and adjusting the fuel pressure
delivered to the nozzle.
al
i
c
pe ease
S
18 g Gr
S
LD arin
Be
ne
Part Number 600190
c
i
ctr
e
l
Die ease
Gr
80
40
ico
Sil
e
ub
.T
z
2o
ish
arn
V
g
5
kin
oc
24
L
54
d
1
e
R
P/N
12
0
16
0
20
0
24
0
Webasto Thermo & Comfort N.A., Inc.
66
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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. This timer has battery backup and will hold its memory if the vehicle battery is
disconnected and will recharge when 12 volt power is restored.
Installation
The timer should be installed in an area protected from the effects of weather and contamination. The timer can be
surface mounted on the vehicle instrument panel or inside the circuit panel (Bus applications) or any place convenient
and accessible.
The timer can be mounted using customer/installer supplied Velcro tape by
sticking one half of the Velcro to the timer and the other to a secure mounting
location. The timer can be mounted with screws in place of Velcro.
Connect the Webasto heater switching harness to the timer.
Refer to the wiring diagram below for directions.
After all connections are made, mount the new timer. Using customer/installer
supplied Velcro tape or screws.
Optionally, an On/Off toggle switch can be installed with the timer. The timer
will work without using the toggle switch however, it’s a nice option to have.
To mount the toggle switch, locate an appropriate mounting location and drill a
½” mounting hole. Refer to the wiring diagram on next page to, connect the
appropriate wires to the toggle switch.
X1
C
Green
A
Red
T1
Red
Webasto Wiring Harness
Black
Black
J
White
White
E
Red
F
Red
G
Brown
B
H
5 12 Volt Positive
4 Optional
D
Brown
F5
Red
Red
3 On Signal
2 Ground
1 12 Volt Positive
BT
Brown
Legend
T1
X1
Timer - 7-Day (NOI)
9-Pin Duetsch Connector
Wiring diagram - NOI Timer
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67
Webasto Thermo & Comfort N.A., Inc.
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. This timer has battery backup and will hold its memory if the vehicle battery is disconnected and
will recharge when 12 volt power is restored.
To set the timer clock:
Press and hold the “Clock” button and by pressing the “Hour” and “Min.” buttons set the clock appropriately. In the
upper left corner you will see the “AM” or “PM” sign.
Setting the timer On/Off functions:
Press the “Timer” button one time. You will see the screen now reads “1” “On” using the day button select the
Appropriate day or days. Look in the upper left hand corner for the “AM” or “PM” sign. Using the day button you can
select one or multiple days. After you have selected the proper day/days and set the appropriate on time, push the
“Timer” button once again. You should now see “1” “Off” using the day button select the appropriate days again.
BE SURE THE DAYS SELECTED MATCH THE SAME DAYS YOU SELECTED FOR TIMER “1” “ON”.
Now set the timer to the appropriate “Off” time. After you have set the timer functions needed, push the “Clock” this
will save your settings and return to the clock.
These steps can be repeated 6 more times giving you multiple on and off settings. It is very important that you set this
timer to the specific needs of each vehicle to optimize the heaters efficiency.
Webasto Product N.A., Inc. s 15083 North Road s Fenton, Michigan 48430
For Technical Assistance in USA Call: (800) 555-4518 s In Canada Call: (800) 667-8900
Visit us on the Web at: www.techwebasto.com (North America) www.webasto.com (Global)
Webasto Thermo & Comfort N.A., Inc.
68
Page 2 of 3
www.techwebasto.com
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”. The manual button can be used as a toggle switch to operate the heater or after you have programmed the
timer for automatic service, push the manual button until the line is over “auto” on the timer. The timer will now turn
the heater on and off at the times preset earlier.
NOTE:
The toggle switch will illuminate green when the heater has an “On” signal. If the toggle switch is in the
“Off” position and the timer has turned the heater on, the toggle will illuminate green. This is an easy
way to identify the heater is in operation. While the timer is “On” the toggle switch will NOT operate
the heater. The toggle switch is a master switch whenever the timer is not in operation.
Safety Precautions:
s The heater must be switched off at filling stations and tank farms as a result of the risk of explosion.
s The heater may not be operated in enclosed spaces (such as garages) as a result of the risk of
poisoning and asphyxiation, even if a timer is used.
s Wherever inflammable vapors or dust may form (for example in the vicinity of fuel, carbon, wood
dust or cereal stores or the like), the heater must be switched off as a result of the risk of explosion.
WARNING
As with other devices whose activation is automated, if a particular
application presents a risk should the heater be automatically activated,
and such a vehicle or application is equipped with a “power cut off”
type switch which prevents devices from activating automatically, then
this timer/heater should be wired into this “power cut off circuit” to
ensure automated activation of the heater does not occur.
Webasto Product N.A., Inc. s 15083 North Road s Fenton, Michigan 48430
For Technical Assistance in USA Call: (800) 555-4518 s In Canada Call: (800) 667-8900
Visit us on the Web at: www.techwebasto.com (North America) www.webasto.com (Global)
www.webasto.us
69
Page 3 of 3
Webasto Thermo & Comfort N.A., Inc.
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. This warranty
period may be superseded by a contractual agreement.*
*Warranty coverage for Marine and Off-road applications containing DBW series heaters and the
CSL Cargo Heaters are limited to a maximum of 3,000 hours of usage. All other models are
limited to 2,000 maximum hours.
Replacement parts are covered for six (6) months or the remainder of the original warranty period,
which ever is longer. Replacement heaters are considered a “Replacement Part.”
The intent of the Webasto warranty is to protect the end-user heater from such defects and provide
free repair and replacement of defective parts in the manner provided herein. During the warranty
period the exclusive remedy will be for Webasto, at their discretion, to repair or replace those parts
which are demonstrated to be defective in material or workmanship.
While warranty is provided to the "end-user", it is to be administered and serviced through an
authorized Webasto dealer in accordance with the Webasto warranty policy or contractual
agreement between Webasto and a second party.
Limitations: Webasto specifically excludes and limits from warranty the following:
· Normal wear of service parts: (fuel nozzles, filters and overheat fuses are not covered).
· Removal and replacement of heater (with the exception of the Thermo Top C).
· Damage to product in transit. All claims must be filed with carrier.
· Improper installation, which is not in accordance with valid, supplied installation instructions or
approved OEM applications.
· Deterioration due to normal wear, corrosion, abuse, damage, accident, improper storage or
operation.
· Modification of product by alteration, use of non-genuine parts or repair by unauthorized
personnel.
· Economic loss for expenses related to travel, vehicle disability, personal injury or other
incidental or consequential damages arising from any breach of this expressed warranty.
Owner's Responsibilities:
1) Service heater at the start of each season by an authorized Webasto dealer (Service parts
including; fuel nozzles, filters and overheat fuses are not covered under warranty).
2) A Warranty Registration Card is included with the sale of each heater. It is the owner's
responsibility to complete this card and return it to Webasto for registration. A proof of
purchase is required for all heaters that are not registered.
This warranty gives you specific legal rights and you may also have other rights which vary by State or Province
THE WARRANTY DESCRIBED IN THIS POLICY SHALL BE IN LIEU OF ANY OTHER WARRANTY,
EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO, ANY IMPLIED WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Webasto Thermo & Comfort N.A., Inc.
70
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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.us
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