Webasto Thermo 90 ST D, Thermo 90 ST B Service And Repair Manual

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Coolant Heater
Thermo 90 ST D (Diesel) Thermo 90 ST B (Gasoline)
Service and Repair Manual
– 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.
WARNINGS.
– Webasto rejects any liability for problems and damage caused by the system being
installed by untrained personnel.
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THERMO 90 ST TABLE OF CONTENTS
Contents Page
1. Introduction 1
1.1 Contents and Purpose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
1.2 Meaning of Signal Words . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.3 Additional Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.4 Safety Information and Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.4.1 General Safety Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.5 Suggestions for Improvements and Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. General Description 3
2.1 Combustion Air Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Heat Exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.3 Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.4 Temperature Limiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2.5 Burner Insert. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.6 Glow Pin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.7 Flame Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.8 Combustion Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.9 Circulating Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.10 Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.11 Metering Pump. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Functional Description 7
3.1 Switching On . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
3.2 Heating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.3 Control Mode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
3.4 Switching Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.5 Malfunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.5.1 Fault Lock-out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
3.5.2 Diagnosis after Fault Lock-out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4. Technical Data 11
5. Troubleshooting 13
5.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
5.2 General Fault Indications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
5.3 Fault Indications on Fault Lock-out . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.4 Visual Check for Assessing the Burner. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6. Functional Tests 19
6.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.2 Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
6.2.1 Setting the CO2 Content . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
6.3 Testing Individual Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.3.1 Resistance Test of the Temperature Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
6.3.2 Resistance Test of the Ceramic Glow Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
6.3.3 Resistance Test on the Flame Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
6.3.4 Testing the Combustion Air Fan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
7. Circuit Diagrams 21
7.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
7.2 Thermo 90 ST Circuit Diagram Legend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
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TABLE OF CONTENTS THERMO 90 ST
8. Servicing Work 25
8.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
8.2 Work on the Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
8.3 Work on the Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
8.4 Heater Trial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
8.5 Service Work. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
8.6 Visual Inspections and Installation Instructions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
8.6.1 Connection to the Vehicle Cooling System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
8.6.2 Connection to the Vehicle Fuel System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
8.6.2.1 Fuel Extraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
8.6.2.2 Fuel Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
8.6.3 Fuel Metering Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
8.6.3.1 Installation Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
8.6.3.2 Installation and Attachment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
8.6.4 Fuel Filter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
8.6.5 Combustion Air Supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
8.6.6 Exhaust Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
8.7 Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
8.7.1 Heater, Removal and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
8.7.1.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
8.7.1.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
8.7.2 Changing the Circulating Pump. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
8.7.3 Changing the Temperature Limiter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
8.7.4 Changing the Temperature Sensor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
8.7.5 Changing the Combustion Air Fan. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
8.8 Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
9. Repair 33
9.1 General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
9.1.1 Work on Stripped-down Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
9.1.1.1 Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
9.1.1.2 Visual Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
9.2 Dismantling and Assembling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
9.2.1 Replacing the Circulating Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
9.2.1.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
9.2.1.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
9.2.2 Replacing the Temperature Limiter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
9.2.2.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
9.2.2.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
9.2.3 Replacing the Temperature Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
9.2.3.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
9.2.3.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
9.2.4 Replacing the Combustion Air Fan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
9.2.4.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
9.2.4.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
9.2.5 Replacing the Burner, Flame Monitor and Glow Pin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
9.2.5.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
9.2.5.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
9.2.6 Replacing the Burner Head . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
9.2.6.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
9.2.6.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
9.2.7 Replacing the Heat Exchanger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
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THERMO 90 ST TABLE OF CONTENTS
9.2.7.1 Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
9.2.7.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
10.Product Information 43
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TABLE OF CONTENTS THERMO 90 ST
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THERMO 90 ST INTRODUCTION
1. INTRODUCTION
1.1 CONTENTS AND PURPOSE
This repair shop manual is intended to assist trained personnel with repairing both the gasoline and the diesel versions of the Thermo 90 ST water heaters.
1.2 MEANING OF SIGNAL WORDS
Throughout this manual, the signal words DANGER, WARNING, CAUTION, and NOTE have the following meanings:
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.
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.
CAUTION: This heading and text style is used to highlight that non-compliance with instructions or procedures may cause damage to equipment.
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.
1.3 ADDITIONAL DOCUMENTATION
1.4.1 GENERAL SAFETY REGULATIONS
The year of first start-up must be indelibly identified on the rating plate by removing the corresponding year number.
The heaters are only licensed for heating the motor vehicle engine and vehicle cabin, not however for heating hazardous material transport space.
The heater is only allowed to be installed in motor vehicles or in independent heating systems with a minimum coolant volume of 6 liters (6.34 quarts).
The heater is not allowed to be installed in the driver’s cab or passenger compartment of vehicles. If the heater is nevertheless installed in such a place, the installation box must be tightly sealed against the vehicle interior. The installation box must have sufficient external ventilation to ensure that a maximum temperature of 40 °C (104 °F) is not exceeded in the box. Malfunctions may occur if the temperature exceeds this level.
WARNING: The heater must not be operated in enclosed areas, such as garages or workshops without an exhaust emissions extraction system, not even using the timer or Telestart, because of the risk of asphyxiation and poisoning.
WARNING: The heater must be switched off at filling stations and fuel tank farms because of the risk of explosion.
CAUTION: Wherever inflammable vapors or dust may form (for example near fuel, coal, wood dust or cereal stores or the like), the heater must be switched off because of the risk of explosion.
This workshop manual contains all the information and instructions required for repairing Thermo 90 ST water heaters. Normally, there is no need to use additional documentation. If required, the installation instructions, the vehicle-specific installation instructions and the operating instructions can be used as well.
1.4 SAFETY INFORMATION AND REGULATIONS
In principle, the general accident prevention regulations and current works safety instructions are applicable. The “General safety regulations” that go beyond the scope of the above regulations are stated below.
Any special safety regulations relevant to this instruction manual will be highlighted in the relevant sections or text passages of the procedures.
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A temperature of 85 °C (185 °F) (storage temperature) must not be exceeded in the vicinity of the control unit (for example when completing painting work on the vehicle).
If this temperature is exceeded, the electronic systems may suffer permanent damage.
Follow the instructions supplied by the vehicle manufacturer to check the cooling water level. The water in the heating circuit of the heater must contain at least 10% branded anti-freeze.
Non-compliance with the installation instructions and the warnings contained therein will lead to the exclusion of all liability 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 revocation of the type licence for the heater and therefore the general operating licence for the vehicle.
Page 8
INTRODUCTION THERMO 90 ST
1.5 SUGGESTIONS FOR IMPROVEMENTS AND C
HANGES
Complaints, improvement suggestions or corrections relating to this workshop manual should be addressed to:
Webasto Product North America, Inc. Technical Documentation Group 15083 North Road Fenton MI 48430
Phone: 810.593.6000
PC-Fax: 810.593.6135
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Page 9
THERMO 90 ST GENERAL DESCRIPTION
2. GENERAL DESCRIPTION
Thermo 90 ST water heaters operate in conjunction with the vehicle’s own heating system and serve
– to heat the cab,
– to defrost the vehicle windows and
– to preheat water-cooled engines.
The water heater operates independently of the engine and is connected to the cooling system, the fuel system and the electrical system of the vehicle.
The concept of the heater is based on the evaporator principle. It is controlled by the temperature sensor and operates intermittently.
Depending on the deviation between the current coolant temperature and the nominal value measured at the temperature sensor, the burner power is regulated between the limits of 1.8 to 7.6 kW in diesel heaters and
2.0 to 7.6 kW in gasoline heaters. When the heating requirement is particularly high (preheating), diesel heaters provide a maximum power of 9.1 kW for up to 2 hours after the heater is switched on.
Thermo 90 ST heater is principally composed of
– the combustion air fan
– the heat exchanger
– the burner insert with combustion pipe
– the circulating pump
To control and monitor it, the heater has
– a control unit (external)
– a flame monitor
– a glow pin
– a temperature sensor
– a temperature limiter
inside it.
The Thermo 90 ST heater is delivered with the control unit already flange-mounted on the combustion air fan.
The fuel supply is provided from an external source using a metering pump.
1
2
11
Figure 1: Thermo 90 ST heater
10
3
4
5
6
1 Combustion air fan 2 Fuel connection 3 Temperature sensor 4 Temperature limiter 5 Heat exchanger 6 Inlet, coolant 7 Circulating pump 8 Outlet, coolant
9
8
7
9 Outlet, exhaust gas 10 Inlet, combustion air 11 Control unit
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Page 10
GENERAL DESCRIPTION THERMO 90 ST
Flame Monitor
Burner Insert
Glow Pin
2.1 COMBUSTION AIR FAN
The combustion air fan supplies the air required for the combustion process from the combustion air inlet to the burner insert.
Figure 2: Combustion air fan
2.3 TEMPERATURE SENSOR
The temperature sensor records the coolant temperature at the coolant outlet of the heater as an electrical resistance. This signal is fed to the control unit where it is processed.
2.4 TEMPERATURE LIMITER
The overheat guard circuit (bimetallic) protects the heater against impermissibly high operating temperatures. The overheat guard circuit trips if the heat exchanger temperature exceeds 127 ±7 °C (260.6 ±10 °F) and switches off the heater. This is a self resetting switch.
2.5 BURNER INSERT
The fuel is distributed over the burner cross-section in the combustion pipe in the burner insert.
2.6 GLOW PIN
The mixture of fuel and air is ignited by the glow pin when the heater is started. The glow pin takes the form of an electrical resistor and is positioned in the burner insert on the side away from the flame.
2.2 HEAT EXCHANGER
In the heat exchanger, the heat generated by combustion is transferred to the coolant circuit.
Temperature Limiter
Temperature Sensor
Figure 4: Burner Assembly
2.7 FLAME MONITOR
Figure 3: Heat exchanger
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The flame monitor is a low-ohm PTC resistor, which changes its resistance depending on the heat emitted by the flame. The signals are fed to the control unit where they are processed. The flame status is monitored by the flame monitor whenever the heater is operating.
Page 11
THERMO 90 ST GENERAL DESCRIPTION
0-90°0-90°
2.8 COMBUSTION PIPE
The mixture of fuel and air burns in the combustion pipe, thus causing the heat exchanger to become hot.
Figure 5: Combustion pipe
2.10 CONTROL UNIT
The control unit is the central component. It guarantees the sequence of functions and monitoring of combustion mode. It is flange-mounted on the combustion air fan.
2.9 CIRCULATING PUMP
The circulating pump ensures that coolant is pumped through the vehicle and heater circuits. The pump is switched on by the control unit and it runs throughout operation of the heater (including in the control pause).
Figure 7: Control unit - flange mounted
2.11 METERING PUMP
The fuel supply and metering for the heater is assured by an external metering pump. It addition, it serves as a shut-off element when the heater is switched off.
The solenoid coil of the metering pump receives its pulses from the microprocessor in the control unit.
Figure 6: Circulating pump
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Figure 8: Fuel metering pump
Page 12
GENERAL DESCRIPTION THERMO 90 ST
This page for your notes.
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Page 13
THERMO 90 ST FUNCTIONAL DESCRIPTION
3. FUNCTIONAL DESCRIPTION
3.1 SWITCHING ON
The “operating indicator” on the digital timer lights up when the “immediate heating” button is pressed.
or
When switching on with the switch, the operating indicator in the switch lights up.
The circulating pump, glow pin and combustion air fan start operating.
3.2 HEATING MODE
Combustion starts after approx. 60 to 140 seconds. Automatically controlled heating operation runs at full load for a maximum of 2 hours.
The vehicle’s own heater fan does not switch on until the heat carrier (coolant) has heated up sufficiently. Once the preset nominal temperature has been reached (see table of regulating temperatures) the heating power is reduced to the lowest part load in small individual steps.
3.3 CONTROL MODE
Diesel Heaters
If the water temperature in the heater is higher than the nominal temperature but has not yet reached the threshold for the control pause and if the temperature then falls back to the nominal temperature within 10 minutes (after reaching this temperature for the first time), the heater switches back to the 9.0 kW heating stage.
When the nominal temperature is reached, the heater is only switched back on again up to the 7.6 kW heating stage.
Gasoline Heaters
The maximum heating power in gasoline heaters is always 7.6 kW.
3.4 SWITCHING OFF
The operating indicator on the digital timer/switch goes out when the heater is switched off. The combustion process will be ended and the run-on phase will start.
The heater switches to the control pause if the temperature of the coolant continues to rise to the threshold of the control pause. The circulating pump, the vehicle’s own heater fan and the operating indicator continue to operate during the control pause.
The heater restarts when the coolant cools to the preset temperature for switching back on.
The circulating pump and the combustion air fan continue to run, however, in order to cool down the heater (run-on) and are switched off automatically after approx. 105 seconds. The heater may be switched on again during the run-on time.
The temperature in the cabin can also be controlled using the vehicle’s own heater fan with a cabin thermostat.
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Page 14
FUNCTIONAL DESCRIPTION THERMO 90 ST
A
B
C
D
E
F
G
1
0
1
0
0
0
0
0
0
1
1
1
1
1
1
/
4
1
/
2
1
/
4
*
30 80 90 75 70 °C
23
22
2120
191716
14
13
1110
181512
986431
25 7
Safety time
*If no flame is formed, the start is automatically repeated (20 s pulse pre­glow, 90 s safety time).
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
Figure 9: Sequence of functions
Sequence of functions for Thermo 90 ST
A. Glow pin
B. Metering pump C. Combustion air fan
D. Flame monitor
E. Operation indicator light
F. Circulating pump
G. Vehicle fan
Switch on Component interrogation Pre-glow 40 s (pulsed)
Metering pump supply 5 – 7 s (1) Metering pump / part load (1/4) Flame monitor take-over Stabilization time Full load Vehicle fan “On” Control range Control pause Flame monitor “Cold” (0)
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Run-on ended (cool-down) Pre-glow 15 – 20 s (pulsed) Metering pump supply 5 – 7 s (1) Metering pump / part load (1/4) Flame monitor take-over Stabilization time Coolant temperature reduced Full load Switch off (run-on) Flame monitor “Cold” (0) Run-on ended (cool-down)
Page 15
THERMO 90 ST FUNCTIONAL DESCRIPTION
3.5 MALFUNCTIONS
3.5.1 FAULT LOCK-OUT
Fuel is supplied for max. 240 seconds if the flame does not start to burn.
Fuel is supplied for max. 240 seconds if the flame goes out during operation.
The fuel supply is shut off if the system overheats (temperature limiter is tripped). If the system overheats the temperature limiter will reset itself after cool down period.
Once the cause of the fault has been eliminated, the fault lock-out is cancelled by switching the heater off and on again.
If the under voltage protection switches off the system for longer than 20 seconds, the fuel supply is interrupted and the heater is shut off. (see table below).
Thermo 90 ST
12 volts 10.5 V - 0.5 V
24 volts 21 V -1 V
CAUTION: A forced reset of the return spring when hot can result in damage to the component.
F 11 Circulating pump interrupt or circulating
pump short circuit
3.5.2.2 VERSION WITH SWITCH
If the system is operated with a switch, the nature of the fault is indicated by a flashing code on an operating indicator light during the run-on time of the heater.
After five short signals, count the long flashes:
1x No start (after 2 attempts to start) 2x Flame failure 3x Under voltage or over voltage 4x Premature flame recognition 5x Flame monitor interrupt or flame monitor
short circuit
6x Temperature sensor interrupt or temperature
sensor short circuit
7x Metering pump interrupt or metering pump
short circuit
8x Fan motor interrupt or fan motor short circuit
or fan motor incorrect speed 9x Glow pin interrupt or glow pin short circuit 10x Overheating 11x Circulating pump interrupt or circulating
pump short circuit
3.5.2 DIAGNOSIS AFTER FAULT LOCK-OUT
Check the fuses and plug connectors.
3.5.2.1 VERSION WITH DIGITAL TIMER
If the system is equipped with a standard timer, a fault message appears on the display of the digital timer after a fault occurs:
F 01 No start (after 2 attempts to start) F 02 Flame failure F 03 Under voltage or over voltage F 04 Premature flame recognition F 05 Flame monitor interrupt or flame monitor
short circuit
F 06 Temperature sensor interrupt or temperature
sensor short circuit
F 07 Metering pump interrupt or metering pump
short circuit
F 08 Fan motor interrupt or fan motor short circuit
or fan motor incorrect speed F 09 Glow pin interrupt or glow pin short circuit F 10 Overheating
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Page 16
FUNCTIONAL DESCRIPTION THERMO 90 ST
This page for your notes.
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Page 17
THERMO 90 ST TECHNICAL DATA
4. TECHNICAL DATA
Except where limit values are specified, the technical data listed in the table refer to the usual heater tolerances of ±10% at an ambient temperature of +20 °C (+68 °F) and at the rated voltage and in rated conditions.
Electrical components:
The control unit, motors for combustion air fan and circulating pump, ceramic glow pin, metering pump, timer, and switch are designed for 12 V or 24 V.
The temperature limiter, temperature sensor and flame monitor are identical on 12 V and 24 V heaters.
HEATER Operation THERMO 90 ST B THERMO 90 ST D
EC licensing symbol ~S299 ~S298 Model Water heater with Ferro-Tec Burner Heat Output Boost max.
Regulating range
Fuel Gasoline Diesel #1, #2, Arctic, PME and
Fuel Consumption Boost max.
Regulating
range Rated Voltage 12 V 12 V 24 V Operating Voltage Range V 10 – 15 V 10 – 15 V 20 – 30 V Nominal power consumption with
circulating pump
Max. ambient temperature: Heater: - Operation
- Storage
Control unit: - Operation
- Storage
Metering pump: - Operation -40... +20 °C (-40... +68 °F) -40... +40 °C (-40... +104 °F)
- Storage -40... +85 °C (-40... +185 °F) Permitted operating pressure Maximum 2.0 bar (29 PSI) Capacity of the heat exchanger 0.15 liters (0.16 quarts) Max. Combustion Air Inlet Temperature +40 °C (104 °F) Minimum capacity of the circuit 6.0 liters (6.34 quarts) Delivery rate of the circulating pump
against 0.15 bar
Boost max. Regulating range
Fuel for Thermo 90 ST B (gasoline):
The fuel specified by the manufacturer must be used.
Fuel for Thermo 90 ST D (diesel/PME):
The diesel fuel specified by the vehicle manufacturer must be used.
We know of no negative influences due to additives.
If fuel is extracted from the vehicle’s tank, follow the additive instructions issued by the vehicle manufacturer.
If you change to low-temperature fuel, the heater must be operated for approx. 15 minutes so that the fuel system is filled with the new fuel.
The Thermo 90 ST D heater is also licensed for use with PME (bio-diesel), which complies with ASTM D6751 and DIN EN 14214.
N/A
2.0 kW – 7.6 kW
(6830 – 25955 BTU/h)
N/A
0.25 l/h – 1.0 l/h
(0.066 g/h – 0.264 g/h)
N/A
37 W – 83 W
-40... +110 °C (90 °C with control unit installed on heater)
-40... +230 °F (194 °F with control unit installed on heater)
-40... +110 °C (90 °C with control unit installed on heater)
-40... +230 °F (194 °F with control unit installed on heater)
-40... +85 °C (-40... +185 °F)
-40... +85 °C (-40... +185 °F)
1650 l/h (435.8 g/h)
9.1 kW (31078 BTU/h)
1.8 kW – 7.6 kW
(6147 – 25955 BTU/h)
Kerosene
1.1 l/h (0.29 g/h)
0.19 l/h – 0.9 l/h
(0.05 g/h – 0.24 g/h)
90 W
37 W – 83 W
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Page 1 of 2
Page 18
TECHNICAL DATA THERMO 90 ST
HEATER Operation THERMO 90 ST B THERMO 90 ST D
CO
In Exhaust Gas
2
(permitted function range)
adjustment values at approx. +20 °C
CO
2
and geographic altitude above sea level Heater dimensions
(* Control unit installed on the heater)
Weight Of Heater 4.8 kg (10.6 lb)
Table 1. Technical data (page 2 of 2)
Maximum 10... 12.0% by volume
Maximum 0 m (0 ft) 500 m (1640 ft) 1000 m (3280 ft)
10% 10.6% 11.3%
tolerance ± 3 mm (± 0.12 in)
L 307 mm (352* mm) [12.08 in (13.85 in*)]
W 131 mm (5.15 in)
H 232 mm (9.13 in)
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Page 19
THERMO 90 ST TROUBLESHOOTING
5. TROUBLESHOOTING
5.1 GENERAL
This section describes how to identify and remedy faults on the Thermo 90 ST air heater.
If a fault occurs, an error code will be output in the display of the timer. If the heater has a switch, the ON control light will flash. In addition, the heater can be checked using a personal computer (see PC heater diagnostic operating manual).
CAUTION: Troubleshooting work demands precise knowledge of the structure and theory of operation of the various components and must be carried out by trained personnel only.
If in doubt, refer to sections 2 and 3 for a description of how the functions interact.
CAUTION: As a rule, fault detection is restricted to the localization of defective components. The following potential sources of malfunctions are not taken into account and should always be checked so that they can then be excluded as the cause of the particular fault:
Corroded plugs
Loose plug contacts
Poor crimp contacts on plugs
Corroded cables and fuses
Corroded battery terminals
Impermissibly high ambient temperature
Conduct a function test in the vehicle after rectifying each fault; switch the heater off and back on again first.
5.2 GENERAL FAULT INDICATIONS
The following table lists the possible general fault indications.
Fault Indication Possible Cause Remedy
Heater switches off automatically
Table 2. General fault indications NOTE: In many cases, the burner may be one
No combustion after start and restart
Flame extinguishes during operation
Heater overheats due to lack or loss of coolant
Voltage failure longer than 20 seconds
Switch off by temperature limiter
No flame recognition on start
possible cause. Perform a visual check in accordance with 5.4
Control unit enters fault lock-out status. Switch heater off and then on again.
Contact a Webasto service facility if heater operation does not start again.
Top up coolant. After the unit has cooled down, press the button on the temperature limiter to reset it before switching on or fit a new temperature limiter.
Check fuses, plug connectors and charge condition of battery
After the unit has cooled down, the temperature limiter will automatically reset itself.
Check flame monitor and connections
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Page 20
TROUBLESHOOTING THERMO 90 ST
5.3 FAULT INDICATIONS ON FAULT LOCK-OUT
NOTE: If the system is operated with a switch, the nature of the fault is indicated by a flashing code on an indicator light during the run-down time of the heater.
Fault indication Possible cause Remedy
After five short signals, count the long flashes.
In the Thermo 90 ST heater with a standard timer, the fault is output on the timer display (see 3.5.2). The following table can be used accordingly.
No function Electrical cabling, fuses
Control unit defective
1 Flashing pulse
(start did not occur)
2 Flashing pulses
(flame failure during burner operation)
3 Flashing pulses
(under voltage)
4 Flashing pulses
(flame monitor continuously hot)
Fuel system
Combustion air/exhaust line
Burner
Fuel supply
Burner
Electrical power supply Check battery
Flame monitor defective Replace flame monitor
Check fuses Check battery connections: + on 12 / – on 9 / + on 3, plug X8
Replace control unit
Check fuel level Check fuel filter Bleed fuel system
Check combustion air/exhaust line for foreign bodies and clean if necessary
Clean burner and change if necessary
Check fuel level Check fuel filter Bleed fuel system
Clean burner and change if necessary
Check electrical connections
5 Flashing pulses
(flame monitor defective)
6 Flashing pulses
(temperature sensor defective)
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Cabling
Flame monitor defective
Cabling
Temperature sensor defective
Check cabling for damage, discontinuity and short-circuit
Replace flame monitor
Check cabling for damage, discontinuity and short-circuit
Replace temperature sensor
Page 1 of 2
Page 21
THERMO 90 ST TROUBLESHOOTING
Fault indication Possible cause Remedy
7 Flashing pulses
(metering pump defective/ (overheating guard circuit defective)
8 Flashing pulses
(combustion air fan defective)
9 Flashing pulses
(glow pin defective)
10 Flashing pulses
(overheating)
11 Flashing pulses
(circulating pump defective)
Coolant circuit
Cabling
Metering pump defective
Cabling
Combustion air fan defective
Cabling
Ceramic glow pin defective
Heater overheats Check coolant and top up if necessary.
Cabling
Check coolant level Bleed coolant circuit
Check cabling for damage, discontinuity and short-circuit
Replace metering pump
Check cabling for damage, discontinuity and short-circuit
Replace combustion air fan
Check cabling for damage, discontinuity and short-circuit
Replace glow pin
After the unit has cooled down, the temperature limiter will aut itself.
Check cabling for damage, discontinuity and short-circuit
Omatically reset
Circulating pump defective
Table 3. Fault indications on fault lock-out
(Page 2 of 2)
5.3.1 PERMANENT HEATER FAULT LOCK-OUT
A permanent fault lock-out is indicated by five short flash pulses with no long flash pulses following.
Failure
F 01 No start / no flame formation F 03 Under voltage or over voltage F 04 Premature flame detection F 05 Flame monitor F 06 Temperature sensor F 07 Fuel pump F 08 Fan motor F 09 Ceramic glow pin F 10 Overheat condition F 11 Coolant circulating pump
F 02 Flame failure After 6
Consecutive number of failed start attempts
consecutive attempts, of any
After 3 one of the listed fault indicators, the heater and control unit are locked out with no further start attempts possible.
consecutive attempts, heater
and control unit are locked out.
Replace circulating pump
NOTE: The permanent fault lock-out serves as a safety feature for the customer.
Remedy
See appropriate fault indication in Table 3.
After eliminating the cause of a heater fault lock-out, remove main fuse, wait  seconds and reinsert fuse. Switch heater on.
Contact a Webasto service facility if heater operation cannot be restored.
Table 4. Permanent heater fault lock-out
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Page 22
TROUBLESHOOTING THERMO 90 ST
5.4 VISUAL CHECK FOR ASSESSING THE BURNER
The burner and the evaporator in the heater display specific characteristics when they must be replaced or do not have any fault source.
The criteria of a correct check are listed below.
5.4.1 BURNER HOUSING
The start air hole (item 9, Fig. 10) must be clear otherwise no start will occur.
Remedy
Carefully remove impurities from the start air hole (e.g. using a 1.5 mm or 1/16 in. diameter wire). Remove the glow pin first.
1
1 Fuel pipe 2 Round seal
9
8
7
6
5
4
2
3
3 Flame monitor 4 Insulation 5 Glow pin 6 Housing 7 Screw 8 Bar 9 Start air hole
Figure 10: Visual check, burner back wall
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Page 23
THERMO 90 ST TROUBLESHOOTING
Air swirl plate
Air holes
Gap between housing and combustion chamber
Combustion chamber
5.4.2 BACK WALL WITH METAL EVAPORATOR
The pilot flame outlet opening (Fig. 11) must be clear otherwise no start will occur.
Remedy
Replace burner
Cracks, flaking as well as black or other discoloration of the evaporator do not lead to burner failure and are not significant.
Coke deposits on the evaporator surface (except for the pilot flame outlet opening) are normal; as a rule, the burner cleans itself due to the load changes from full load to part load and part load to full load.
Pilot flame outlet opening
Metal evaporator, gasoline
Pilot flame outlet opening
5.4.3 COMBUSTION CHAMBER
The combustion chamber (Fig. 12) should not be damaged (e.g. dented). A dented combustion chamber can lead to poor combustion or carbon build-up in the heater.
Remedy
Replace burner
The air holes (Fig. 12) in the combustion chamber must not be blocked up by carbon deposits. If the air holes are blocked up by carbon deposits, this may result in failure of combustion to start or to run effectively.
Remedy
Carefully scratch clear the air holes
5.4.4 COMPLETE BURNER
The cables of the glow pin and flame monitor must be routed as shown in Fig. 10.
The screw connection of the housing and combustion chamber (Fig. 12) must be tight.
The housing and the combustion chamber (Fig. 12) must be firmly connected together and there must not be any play (check by moving the fuel pipe slightly).
The round sealing ring (item 2, Fig. 10) must evenly surround the fuel pipe and must not leak.
The distance (gap) between the edge of the housing and the top edge of the combustion chamber (Fig. 12) does not have to be even all the way around.
The insulation (item 4, Fig. 10) must not be missing.
Metal evaporator, diesel
Figure 11: Visual check, pilot flame outlet opening
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Figure 12: Visual check, complete burner
Page 24
TROUBLESHOOTING THERMO 90 ST
This page for your notes.
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Page 25
THERMO 90 ST FUNCTIONAL TESTS
6. FUNCTIONAL TESTS
6.1 GENERAL
This section describes the tests conducted on the heater when it is installed and not installed to verify that it is in working order.
WARNING: The heater must not be operated in enclosed areas such as garages and workshops without an emissions extraction system.
6.2 SETTINGS
6.2.1 SETTING THE CO2 CONTENT
It is permitted for the factory-set combustion air quantity to be modified. This is achieved by turning the air regulating screw.
Setting procedure
Turning clockwise: CO run for about 5 minutes before measuring).
Rough setting: Screw the adjusting screw fully in clockwise and then one turn back
value is reduced (let the heater
2
6.3.2 RESISTANCE TEST OF THE CERAMIC GLOW PIN
If you conduct this electrical test with a digital multimeter, the glow pin should have the following values:
Glow pin: 12 V (red) 24 V (green)
Resistance at 25 °C : 0.3 ... 0.6 1.3 ... 1.44 Resistance at 77 °F : 0.3 ... 0.6 1.3 ... 1.44
Test current: < 5 mA < 5 mA
6.3.3 RESISTANCE TEST ON THE FLAME MONITOR
If you conduct this test with a digital multimeter, the flame monitor must have the following values:
Cold Testing:
Resistance at 25 °C (77 °F): 3.0 ± 0.4
Test current: < 5mA
Hot Testing:
Resistance at 800 ± 20 °C: 8 ± 1.0 Resistance at 1472 ± 36 °F: 8 ± 1.0
(ceramic rod at red heat over length of approx. 20 mm)
Test current: < 5 mA
CAUTION: .The CO instruments must be calibrated.
measuring
2
6.3 TESTING INDIVIDUAL COMPONENTS
6.3.1 RESISTANCE TEST OF THE TEMPERATURE
ENSOR
S
If you conduct this electrical test with a digital multimeter, the temperature sensor should have the following values at room temperature:
Resistance at 25 °C: 990 ... 1010
Test current: < 1 mA
6.3.4 TESTING THE COMBUSTION AIR FAN
The motor speed test must be performed with the heater assembled and in the operating voltage range. Listen out for grinding noises.
NOTE: The cover must be removed from the fan in order to check the motor speed. Install a new seal before re-installing.
CAUTION: Make sure the detent lugs do not break off. Fit a new cover and a new seal if the detent lugs have broken off.
Speed in control range min. 1800 rpm (±9%)
Speed in control range max. 5600 rpm (±9%)
Install a new combustion air fan if the speeds are outside tolerance (see 9.2.4).
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Page 26
FUNCTIONAL TESTS THERMO 90 ST
This page for your notes.
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Page 27
THERMO 90 ST CIRCUIT DIAGRAMS
7. CIRCUIT DIAGRAMS
7.1 GENERAL
The circuit diagrams (Figs. 13 and 14) show the possible circuits for the Thermo 90 ST heater with
– Standard switch
– Standard timer
7.2 THERMO 90 ST CIRCUIT DIAGRAM LEGEND
Digital timer P2:
Connection X14 to Red jumper of switch harness results in continuous operation with immediate heating (recommended for trucks requiring sleeper heating)
Connection X14 to vehicle ignition connection results in variable heating duration that can be programmed (10 min. to 120 min.); default setting 120 min. when ignition key is switched off. (Recommended for School bus, Coach and Transit vehicles.)
Optional connection to vehicle instrumentation
panel lighting circuit.
Item Designation Comment
H3 Symbol light Light (in item P2)
H6 Red LED Immediate heat
button light, ready indicator, switch-on control (in item P2)
K1 Relay Vehicle fan interface
harness option
M1 Motor Combustion air fan
M2 Motor Circulating pump
P2 Digital timer 1531 For programmed
operation
S1 Toggle switch ON/OFF
X1 Plug connector, 4-pin To item A2
X2 Plug connector, 2-pin To item A2
X3 Plug connector, 2-pin To item A2
X4 Plug connector, 2-pin To item A2
X5 Plug connector, 2-pin To item A2
X6 Plug connector, 2-pin To item A2
The following Table applies to Figures 13 and 14.
Item Designation Comment
A1 Heater
A2 Control module
B1 Flame sensor
B2 Temperature sensor
B3 Temperature limiter/
Overheating guard
B4 Room thermostat
BT Battery Vehicle battery
DS Illuminated toggle Operating indicator (in
item S1)
E Glow plug
F1 Fuse 10 A ATM mini flat fuse
F2 Fuse 5 A ATM mini flat fuse
F3 Fuse 20 A ATM mini flat fuse
H1 “Heating” symbol in
the display
Operating indicator (in item P2)
X7 Plug connector, 2-pin To item A2
X8 12-pin plug
connection
X9 12-pin plug
connection
X10 Plug connector, 2-pin W-Bus Diagnostics
X11 Plug connector, 2-pin To Y1
X12 9-pin plug connection Power/Control
X13 Plug connector, 8-pin To X9 of item P2
X14 Plug connector, 1-pin To pin-10 of item X9
X15 Plug connector, 3-pin To optional blower
X16 5-pin relay socket Vehicle fan interface
Y1 Metering pump Fuel pump for heater
To it e m A 2
To item P2
Harness
(see
)
interface systems (Sleeper Pak™)
harness option
www.webasto.us 21 Webasto Product N.A., Inc.
Page 28
CIRCUIT DIAGRAMS THERMO 90 ST
Yellow
Brown
Brown
Brown
Brown
Black
Blue
Black
Blue
White/Blue
Violet/Blue
Gray
Orange
Orange
Green
Blue
Brown
VioletViolet
Violet
Gray
Gray
Green
Green
Red
Yellow
E
M1
MM
M2
B3
B1 B2
Y1
A1
F3
F2
F1
Red
White
Red Red
Red
1
2
X10
Yellow/Red
A
B
CDE F
BDC
S1
DS
K1
86
85
87
30
Brown
Brown
Brown
RedRed
Red
BT
F5
Black
White
Red
A
EFGHJ
Brown
Gray
Red/Black
Black
Black
WhiteWhite
Violet
White
White
Violet
Brown
Black
Green
Red
Red
Red
Red
Brown
Brown
Brown
White
White
Brown
87a
1
5
2
4
3
ABC
X15
X12
X16
B4
Green
Green
White
White
Black
Violet
Black
Black
Optional Blower Interface Harness P/N 905613B
Black
Green
White
12568
10
11
A2
X8
4
3
7
9
12
12 1 2122224 11112
X2 X4 X1 X5 X6 X7 X3
X11
12
12V +
GND
1
1
0
0
M2
A
B
X15
X12
1 2
X11
X10
X8
X4/X5/X6/X7
2
1
X3
2
C
1 2
1
2
1
3
5
7
9
11
1
Figure 13: Thermo 90 ST with On/Off switch - connection diagram (Includes optional blower interface harness)
Webasto Product N.A., Inc. 22 www.techwebasto.com
EB2 B3
B1
M1
X2
X1
1
2
1
4
3
2
Page 29
THERMO 90 ST CIRCUIT DIAGRAMS
2
8
11
101
12
7
4
H3
P2
H1
H6
6
3
4
1
2
7
5
8
X1
X8
X13
X11
X10
X12
X15
X9
X3
X4/X5/X6/X7
3
6
9
12
1 2
1 2
1
2
A
B
C
3
4
6
7
8
5
1
2
EB2 B3
M1
M2
B1
1
3
5
7
9
11
3
4
1
2
1
2
1
2
1
2
X2
F3
F2
F1
Red
White
Red Red
Red
X8
1
2
4
3
5
6
789
10
11
12
12 1 2122224 11112
1
2
X10
Yellow/Red
Yellow
Brown
Brown
Brown
Brown
Black
Blue
Black
Blue
White/Blue
Violet/Blue
Gray
Orange
Orange
Green
Blue
Brown
VioletViolet
Violet
Gray
Gray
Green
Green
Red
Yellow
A
B
CDE F
BDC
Brown
Brown
Brown
RedRed
Red
BT
F5
A
EFGHJ
Brown
Gray
Red/Black
Black
Black
WhiteWhite
Violet
White
Violet
Brown
Black
Green
Red
Red
Red
Red
Brown
Brown
Brown
White
White
Brown
E
M1
MM
M2
B3
B1 B2
Y1
A1
A2
ABC
Violet
Brown
Brown
Red
Yellow
Black
Gray
Black
Red
White
Violet
X13
X14
X9
12
X2 X4 X1 X5 X6 X7 X3
X11
X15
X12
Figure 14: Thermo 90 ST with 7-day digital timer model 1531 - connection diagram
www.webasto.us 23 Webasto Product N.A., Inc.
Page 30
CIRCUIT DIAGRAMS THERMO 90 ST
This page for your notes.
Webasto Product N.A., Inc. 24 www.techwebasto.com
Page 31
THERMO 90 ST SERVICING WORK
8. SERVICING WORK
8.1 GENERAL
This section describes the servicing work that can be carried out on the heater when it is installed.
8.2 WORK ON THE HEATER
Disconnect the main power cable from the vehicle’s battery before carrying out any work on the heater. The main battery power must not be disconnected whilst the heater is operating or slowing down as a result of the risk of the heater overheating and the overheating guard thus being tripped.
If you wish to carry out extensive repair work on the heater, it may be a good idea to remove it completely. After working on the heating circuit, top up with a coolant mixture of water and antifreeze according to the manufacturer’s instructions and carefully bleed the heating circuit.
Refer to the relevant installation instructions and the installation proposal for the heater for the specific vehicle for repairs that necessitate the installation position being changed.
8.3 WORK ON THE VEHICLE
CAUTION: A temperature of 90 °C (194 °F) must not be exceeded in the vicinity of the heater in any circumstances (for example when completing painting work on the vehicle). See Section 4.
8.4 HEATER TRIAL
WARNING: The heater must not be operated in enclosed areas such as garages and workshops without an emissions extraction system, even if the heater is equipped with a timer.
8.5 SERVICE WORK
NOTE: The heater should be operated for approximately 20 minutes every 4 weeks to prevent mechanical parts seizing.
The following service work is to be carried out after or before each heating period to maintain the functional reliability of the heater:
Clean the exterior of the heater (avoid the ingress of water).
Check the electrical connections for contact corrosion and to ensure that they are secure.
Check the exhaust and combustion air lines for signs of damage and to ensure that they are clear.
Check the fuel line and filter for leaks.
Check the coolant circuit and circulating pump for leaks.
Inspect hoses for cracks.
Replace the fuel filter if there is one.
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Page 32
SERVICING WORK THERMO 90 ST
15
14
13
11 Fuel standpipe
12 Heat exchanger - vehicle heating
13 Digital timer
14 Coolant hose to heater inlet
15 Return coolant hose from heater
11
12
6
7
1
10
9
2
8
3
5
4
6 Fuse block
7 Vehicle batteries
8 Fuel line
9 Fuel metering pump
1 Thermo 90 ST water heater
2 Control unit
3 Circulating pump
4 Combustion air intake
10 Fuel filter (optional)
5 Exhaust outlet with muffler
Figure 15: Installation example of a heater in a truck
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Page 33
THERMO 90 ST SERVICING WORK
iØ2mm
iØ2mm
iØ2mm
iØ2mm
I
2
I
2
I
1
I
1
max. 3m (9.8 ft.)
H
S
I
2
I
1
+
10 m (32.8 ft.) 1.2 m (3.9 ft.) 8.8 m (28.8 ft.)
I
1
I
2
8.6 VISUAL INSPECTIONS AND INSTALLATION I
NSTRUCTIONS
8.6.1 CONNECTION TO THE VEHICLE COOLING
YSTEM
S
In thermostat circuits, only use thermostats which start to open at < 65 °C (< 149 °F).
The heater should be installed in as low a position as possible to allow the heater and circulating pump to be bled automatically. This is particularly important as the circulating pump is not self-priming.
The heater is connected to the vehicle cooling system as shown in Fig. 15. The system must contain at least 6 liters (6.34 quarts) of coolant.
The coolant hoses supplied by Webasto must always be used. If you do not use these hoses, the hoses that you do use must comply with DIN 73411. The hoses must be installed without kinks rising if possible.
Hose connections must be supported by hose clips to prevent them slipping.
and (to ensure proper bleeding)
Permissible fuel inflow
height H (m)
At max. pressure (bar) in
fuel line
0.00 m (0.00 in.) 0.20 bar (2.9 PSI)
1.00 m (39.4 in.) 0.11 bar (1.6 PSI)
2.00 m (78.7 in.) 0.03 bar (0.44 PSI)
Maximum fuel intake
height S (m)
At max. negative
pressure (bar) in fuel tank
0.00 m (0.00 in.) -0.10 bar (-1.45 PSI)
0.50 m (19.7 in.) -0.06 bar (-0.87 PSI)
1.00 m (39.4 in.) -0.02 bar (-0.29 PSI)
NOTE: A sign must be affixed to the fuel filler neck warning that the heater must be switched off before refuelling.
NOTE: The hose clips must be tightened with a torque of 4 Nm.
The cooling system must be bled carefully before using the heater for the first time or after replacing the coolant. The heater and lines should be installed in such a way as to ensure static bleeding.
Proper bleeding can be identified by the circulating pump operating almost silently. Poor bleeding may cause the resetting temperature limiter to trip while the heater is in operation.
8.6.2 CONNECTION TO THE VEHICLE FUEL SYSTEM
The fuel is taken from the vehicle fuel tank or from a separate fuel tank.
The values for the maximum pressure at the fuel extraction point are shown in the table below.
Figure 16: Fuel supply
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Page 34
SERVICING WORK THERMO 90 ST
> 25 mm (> 1 in.)
25 mm (1 in.)
Plastic tank
Sealing ring
8.6.2.1 FUEL EXTRACTION
Vehicles with Diesel Engines
The fuel must be taken from the vehicle fuel tank or from a separate tank (Figs. 17, 18 and 19).
Hole pattern
Max. depth
Sealing ring
Metal tank fitting or sender plate
Figure 19: Fuel standpipe for a plastic or metal tank
(extraction through metal tank fitting)
Figure 17: Webasto fuel standpipe
Figure 18: Fuel extractor from a plastic or metal tank
NOTE: Only use this style of standpipe with metal fuel tanks.
(extraction through tank drain screw)
NOTE: Deburr the cut on the fuel extractor after sawing it off and remove any metal chips
Vehicles with Gasoline Engines
The heater must be integrated into the return line of fuel systems in carburetor and injection engines with a return line.
In carburetor engines without a return line the heater must be integrated into the fuel system in the supply line between the fuel tank and the vehicle pump.
IMPORTANT!
A fuel feed line can normally be identified by the fact that a fuel filter is installed in it.
If there is an evaporation tank in the vehicle’s fuel system, the fuel must be extracted upstream of the evaporation tank.
Fuel may only be taken from the supply or return line using the special Webasto fuel extractor tee
(Fig. 20). The fuel extractor must be fitted in such a way that any air or gas bubbles are automatically discharged towards the tank (Fig. 20). Air or gas bubbles may be produced in the vehicle’s fuel line if there are leaks in the carburetor
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Page 35
THERMO 90 ST SERVICING WORK
a= 6Ø
8Ø 10Ø 12Ø
0-60°
Ø5
0-60° 0-60°
0-60° 0-60°
0-60°
From Tank
To Engine
To Fuel Metering Pump
Clamp
Bubble
Bubble
Wrong
Correct
0-90°0-90°
Install in horizontal position only!
12 V and 24 V – Diesel DP 30 (with damper)
or vehicle fuel pump or if the ambient temperature is higher than the evaporation temperature of the fuel.
The fuel extractor should not be located near the engine, as gas bubbles may form in the lines on account of heat radiated from the engine. This may cause problems during combustion.
When installing the heater in a vehicle with fuel injection system, it is important to establish whether the fuel pump is located inside or outside the tank. If the fuel pump is located inside the tank, fuel can only be extracted from the return line. In this case it must be ensured that the return line continues almost to the bottom of the tank and is not sealed by a non-return valve. If this is not the case the return line may be extended. If the fuel pump is installed outside the tank, the fuel connection may be made between the tank and the fuel pump.
Unsupported fuel lines must be secured to prevent them sagging. They must be installed in such a way that they cannot be damaged by flying road debris and high temperatures (exhaust line).
The fuel lines must be secure at the connections using hose clips to prevent their slipping.
Connecting Two Fuel Lines with a Hose
The correct procedure for connecting fuel lines with hosing is shown in Fig. 21.
Figure 20: Webasto fuel extractor tee installation
8.6.2.2 FUEL LINES
Only steel, copper and plastic lines of plasticized, light and temperature-stabilized PA11 or PA12 (for example Mecanyl RWTL) according to DIN 73378 may be used for the fuel lines.
NOTE: Cut Mecanyl lines without burr and do not crush them. Do not cut them with side­cutting pliers.
Since the lines cannot normally be routed with a constant
rising gradient, the internal diameter must not be allowed to exceed a certain size. Air or gas bubbles will accumulate in lines with an internal diameter of more than 4 mm (5/32 in) and these will cause malfunctions if the lines sag or are routed downwards. The diameters specified in Fig. 16 will ensure that bubbles do not form.
The lines should not be routed downwards from the metering pump to the heater.
www.webasto.us 29 Webasto Product N.A., Inc.
Figure 21: Fuel line connections
8.6.3 FUEL METERING PUMP
The metering pump is a combined delivery, metering and shut-off system and is subject to certain installation criteria (Fig. 16 and 22).
Figure 22: Metering pump, installation position and
attachment
8.6.3.1 INSTALLATION POSITION
Before installing the fuel metering pump, ensure that the maximum pressure occurring at the fuel pickup point is less than 0.2 bar (2.9 PSI).
Page 36
SERVICING WORK THERMO 90 ST
A
Ø 5
0° - 90°
10°
It is advisable to install the metering pump in a cool place. The maximum ambient temperature must not exceed +20 °C (+68 °F) for gasoline and +40 °C (+104 °F) for diesel at any time during operation.
The metering pump and fuel lines must not be installed within range of the radiated heat from hot vehicle parts. A heat shield must be used if necessary.
The pump should ideally be installed near the tank.
8.6.3.2 INSTALLATION AND ATTACHMENT
The metering pump must be secured with a vibration­damping mounting. Its installation position is limited as shown in Fig. 22 in order to ensure effective automatic bleeding.
As a result of the risk of corrosion, only genuine Webasto parts may be used for the plug connections between the metering pump and the metering pump wiring harness.
8.6.4 FUEL FILTER
Only a Webasto filter, P/N 50487171A, is allowed to be used if the fuel is expected to be contaminated. Install vertically if possible, however at most horizontally (check flow direction).
The combustion air inlet must not be routed above the exhaust outlet.
NOTE: If the combustion air intake line cannot be installed so that it slopes downwards, a water drain hole with a diameter of 4 mm (5/32 in) is to be made at its lowest point.
If the heater is installed in a general installation space near the vehicle’s fuel tank, the combustion air must be taken in from the outside and the exhaust fumes discharged into the atmosphere. The openings must be splash-proof.
2
A ventilation opening measuring at least 6 cm
(1 in2) is required if the heater is installed in an enclosed box. The size of the ventilation opening must be increased accordingly if the temperature in the box exceeds the permitted ambient temperature of the heater (see Technical data).
8.6.6 EXHAUST LINE
The exhaust line (internal diameter 38 mm) can be installed with a length of 0.5 m to 5 m and several bends (360° altogether, minimum bending radius 85 mm). The exhaust muffler is essential and must be installed near the heater.
Figure 23: Fuel filter
8.6.5 COMBUSTION AIR SUPPLY
Under no circumstances may the combustion air be taken from areas occupied by people. The combustion air intake opening must not point in the direction of travel.
It must be located so that it cannot become clogged with dirt or snow and cannot suck in splashing water.
The combustion air intake line (internal diameter at least 30 mm) may be 0.5 m to 5 m long with several bends totalling 360°. Minimum bending radius is 45 mm.
An attachment is required no further than 150 mm (6 in) from the end of the exhaust pipe to ensure that the angle of 90° ±10° is achieved.
Discharge direction more or less vertical 90° ± 10°
Figure 24: Exhaust pipe opening, installation position
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Page 37
THERMO 90 ST SERVICING WORK
The opening of the exhaust pipe must not point towards the front of the vehicle (see Figure 24).
The exhaust pipe opening must be located so that it cannot become clogged with snow and mud.
Rigid pipes of unalloyed or alloyed steel with a minimum wall thickness of 1.0 mm or flexible piping of alloyed steel only must be used as the exhaust line. The exhaust pipe is secured to the heater using a clamping collar, for example. See your local jurisdiction for statutory regulations for other requirements that may be in force.
8.7 REMOVAL AND INSTALLATION
CAUTION: When the heater is installed, only the following dismantling or removal procedures are permitted providing the upper cover cap is accessible and can be removed, and there is sufficient room for removal:
– Changing the circulating pump
– Changing the temperature limiter
– Changing the temperature sensor
– Changing the combustion air fan
– Changing the control unit
2. Connect the coolant hoses and secure with hose clips. Tighten the hose clips to 5 Nm (44 lb-in).
3. Secure the connection for the combustion air inlet on the heater.
4. Secure the connections for the combustion air inlet and exhaust outlet on the heater.
5. Connect the wiring harness plug to the heater.
6. Put on the top cover cap and lock it in place.
7. Connect the battery.
8. Bleed the fuel supply system.
9. Bleed the coolant circuit.
8.7.2 CHANGING THE CIRCULATING PUMP
NOTE: The process for changing the circulating pump is the same irrespective of whether the heater is installed or removed. Change as described in 9.2.1.
8.7.3 CHANGING THE TEMPERATURE LIMITER
NOTE: The process for changing the temperature limiter is the same irrespective of whether the heater is installed or removed. Change as described in 9.2.2.
8.7.1 HEATER, REMOVAL AND INSTALLATION
8.7.1.1 REMOVAL
1. Disconnect the battery.
2. Remove the upper cover cap.
3. Disconnect the wiring harness plug from the heater.
4. Disconnect the connection for the combustion air inlet on the heater.
5. Unfasten the hose clips and pull the coolant hoses off the heater.
6. Disconnect the connections for the combustion air inlet and exhaust outlet on the heater.
7. Remove three screws and washers from the heater holder.
8. Remove the heater.
8.7.1.2 INSTALLATION
1. Position the heater in its installation position and screw in 3 screws with washers to attach it.
8.7.4 CHANGING THE TEMPERATURE SENSOR
NOTE: The process for changing the temperature sensor is the same irrespective of whether the heater is installed or removed. Change as described in 9.2.3.
8.7.5 CHANGING THE COMBUSTION AIR FAN
NOTE: The process for changing the combustion air fan is the same irrespective of whether the heater is installed or removed. Change as described in 9.2.4.
8.8 START-UP
After you have installed the heater, bleed the coolant circuit and the fuel supply system carefully. Comply with the instructions given by the vehicle manufacturer when doing this. During the trial run, check all coolant and fuel connections for leaks and to ensure that they are secure. If the heater suffers a fault during operation, the fault must be located and remedied (see section 5).
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Page 38
SERVICING WORK THERMO 90 ST
This page for your notes.
Webasto Product N.A., Inc. 32 www.techwebasto.com
Page 39
THERMO 90 ST REPAIR
9. REPAIR
9.1 GENERAL
This section describes the repair work that may be carried out on the Thermo 90 ST heater after it has been removed from the vehicle. Any further dismantling will invalidate the warranty. Only use the spare parts from the appropriate spare parts kits for assembling the heater.
9.1.1 WORK ON STRIPPED-DOWN COMPONENTS
CAUTION: All sealing elements between the stripped-down components must always be discarded and replaced with new.
9.1.1.1 CLEANING
Clean all stripped-down components.
Remove all seal residue on the components carefully using a suitable tool.
9.1.1.2 VISUAL INSPECTION
Check all components for damage (cracks, deformation, wear, etc.) and fit new ones if necessary.
Inspect the plugs and cables for corrosion, loose contacts, crimping faults, etc. and repair them if necessary.
Check plug contacts for signs of corrosion and to ensure they are secure. Repair them if necessary.
9.2 DISMANTLING AND ASSEMBLING
9.2.1 REPLACING THE CIRCULATING PUMP
9.2.1.1 REMOVAL
1. Remove the heater (see 8.7.1.1).
2. Remove the screws (4, Fig. 25).
3. Remove the clip (3) and circulating pump (2).
4. Unplug electrical cable from control unit.
5. Complete the work on stripped-down components (see 9.1.1).
9.2.1.2 INSTALLATION
1. Apply acid-free grease (Vaseline) to the sealing ring (1, Fig. 25).
2. Place the circulating pump (2, Fig. 25) in the assembly position and attach with the clip (3) and screws (4).
3. Tighten the screws (4) to 3 Nm (26.5 lb-in) ±10%.
4. Plug electrical cable into control unit.
5. Install the heater (see 8.7.1.2).
www.webasto.us 33 Webasto Product N.A., Inc.
Page 40
REPAIR THERMO 90 ST
1 Sealing ring 2 Circulating pump 3 Clip 4 Screw (2)
1
2
3
4
Figure 25: Replacing the circulating pump
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Page 41
THERMO 90 ST REPAIR
9.2.2 REPLACING THE TEMPERATURE LIMITER
9.2.2.1 REMOVAL
NOTE: The temperature limiter only has to be removed if it is being replaced with a new one. The function must be checked in the installed condition.
1. Remove the heater (see 8.7.1.1).
2. Remove the clip (2, Fig. 26) and pull off the protective cap (1).
3. Use a screwdriver to lever off the retaining spring and remove the temperature limiter (3).
4. Unplug electrical cable from control unit.
5. Complete the work on stripped-down components (see 9.1.1).
NOTE: It is essential to fit a new temperature limiter to replace a removed one!
9.2.2.2 INSTALLATION
CAUTION: Incorrect installation will cause the heat exchanger to melt.
9.2.3 REPLACING THE TEMPERATURE SENSOR
9.2.3.1 REMOVAL
1. Remove the heater (see 8.7.1.1).
WARNING: Leaking hot coolant can cause burns.
2. Unscrew and remove the temperature sensor (6, Fig. 26) and remove it together with the round sealing ring (5).
3. Unplug electrical cable from control unit.
4. Complete the work on stripped-down components (see 9.1.1).
9.2.3.2 INSTALLATION
1. Apply acid-free grease (Vaseline) to the round sealing ring (5, Fig. 26).
2. Fit the temperature sensor (6) with the round sealing ring (5) and screw it into the heat exchanger (4). Tighten to 1.5 Nm (13.3 lb-in) ±10%.
3. Plug electrical cable into control unit.
4. Install the heater (see 8.7.1.2).
1. Insert the new temperature limiter (3, Fig. 26) into the heat exchanger (4) and press in the retaining spring.
NOTE: You must be able to hear and feel the spring clip into the groove. Only then is the temperature limiter in the correct installation position.
If you do not hear and feel the spring clip in:
Clean the contact surface of the temperature limiter on the heat exchanger
Clean the groove in the heat exchanger
Ensure that the detent lugs are present on both sides of the spring. Fit a new temperature limiter if necessary.
2. Put on the protective cap (1) and secure it with the clip (2).
3. Tighten the clip to 1 Nm (8.8 lb-in) ±10%.
4. Plug electrical cable into control unit.
5. Install the heater (see 8.7.1.2).
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Page 42
REPAIR THERMO 90 ST
1
2
3
4
6
5
1 Protective cap 2 Clamp 3 Temperature limiter 4 Heat exchanger 5 Round sealing ring 6 Temperature sensor
Figure 26: Replacing the temperature limiter and
temperature sensor
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Page 43
THERMO 90 ST REPAIR
9.2.4 REPLACING THE COMBUSTION AIR FAN
9.2.4.1 REMOVAL
1. Remove the heater (see 8.7.1.1).
2. Remove the screws (2, Fig. 27).
3. Pull the combustion air fan (1) off the burner head (4) and remove together with the shaped sealing ring (3).
NOTE: Remove the control unit if necessary from the Thermo 90 ST heater with flange­mounted control unit.
4. Unplug electrical cable from control unit.
5. Complete the work on stripped-down components (see 9.1.1).
1 Combustion air fan 2 Screw (2) 3 Shaped sealing ring 4 Burner head 5 Control unit
2
3
9.2.4.2 INSTALLATION
NOTE: Insert the shaped seal (3, Fig. 27) correctly and grease it (e.g. with Vaseline). Take care not to squash it.
1. Fit the new shaped sealing ring (3) onto the combustion air fan (1). Bring the fan into the assembly position and secure it with screws (2).
2. Tighten the screws (2) to 3 Nm (26.5 lb-in) ±10%.
NOTE: Install the control unit if necessary on the Thermo 90 ST heater with flange-mounted control unit.
3. Plug electrical cable into control unit.
4. Install the heater (see 8.7.1.2).
5
Figure 27: Replacing the combustion air fan
www.webasto.us 37 Webasto Product N.A., Inc.
4
1
Page 44
REPAIR THERMO 90 ST
Glow pin
Flame monitor
9.2.5 REPLACING THE BURNER, FLAME MONITOR AND
LOW PIN
G
9.2.5.1 REMOVAL
1. Remove the heater (see 8.7.1.1).
2. Remove the combustion air fan (see 9.2.4.1).
3. Remove the screw (5, Fig. 28) and washer (4).
4. Remove the nuts (10) and pull off the bar (8).
5. Pull the grommets (11 and 12) out of the slots in the housing of the combustion pipe (3).
6. Pull the grommet (13) and burner (1) out of the burner head and remove with the air swirl plate (2).
7. Pull the flame monitor (7) and glow pin (6) from the burner (1) and remove.
8. Perform a visual check for assessing the burner (see 5.4).
9. Complete the work on stripped-down components (see 9.1.1).
9.2.5.2 INSTALLATION
1. Place the air swirl plate (2, Fig. 28) onto the burner (1).
2. Carefully insert the flame monitor (7) and glow pin (6) into the burner up to the stop and push the grommets (11 and 12) into the slots in the housing of the burner pipe (3).
3. Insert the burner (1) and grommet (13) into the burner head (3).
CAUTION: During the following procedure, make sure that the cables of the flame monitor (7) and the glow pin (6) are routed as shown in the figure.
4. Push the insulation (9) onto the bar (8) and bring the bar into the assembly position.
NOTE: Route the cable of the flame monitor and the glow pin as shown in the figure!
Webasto Product N.A., Inc. 38 www.techwebasto.com
5. Secure the bar (8) using the nuts (10). Tighten the nuts to 3 Nm (26.5 lb-in) ±10%.
6. Secure the fuel line using the screw (5) and washer (4). Tighten the screw to 3 Nm (26.5 lb-in) ±10%.
7. Install the combustion air fan (see 9.2.4.2).
8. Plug in any electrical cables removed from the control unit.
9. Install the heater (see 8.7.1.2).
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THERMO 90 ST REPAIR
1
13
12
10
9
11
1 Burner 2 Air swirl plate 3 Burner head 4 Washer 5 Screw 6 Glow pin 7 Flame monitor 8 Bar 9 Insulation 10 Nut (2) 11 Grommet 12 Grommet 13 Grommet
8
7
6
3
2
4
5
Figure 28: Replacing the burner, flame monitor and
glow pin
www.webasto.us 39 Webasto Product N.A., Inc.
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REPAIR THERMO 90 ST
9.2.6 REPLACING THE BURNER HEAD
9.2.6.1 REMOVAL
1. Remove the heater (see 8.7.1.1).
2. Remove the combustion air fan (see 9.2.4.1).
3. Remove the burner, flame monitor and glow pin (see 9.2.5.1).
4. Remove the mounting screw of the V-clamping collar (2, Fig. 29 and pull off the clamping collar.
5. Pull out and remove the burner head (1) from the heat exchanger (3).
6. Complete the work on stripped-down components (see 9.1.1).
9.2.6.2 INSTALLATION
NOTE: The burner head and exhaust outlet port can also be aligned during installation in the vehicle.
1. Guide the burner head (1, Fig. 29) into the heat exchanger (3), align it if necessary and secure with the V-clamping collar (2).
2. If necessary, tighten the mounting screw of the V-clamping collar to 3 Nm (26.5 lb-in) ±10%.
3. Install the burner, flame monitor and glow pin (see 9.2.5.2).
4. Fit the combustion air fan (see 9.2.4.2).
5. Install the heater (see 8.7.1.2).
1 Burner head 2 V-clamping collar 3 Heat exchanger
3
2
1
Figure 29: Replacing the burner head
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THERMO 90 ST REPAIR
9.2.7 REPLACING THE HEAT EXCHANGER
9.2.7.1 REMOVAL
1. Remove the heater (see 8.7.1.1).
2. Remove the circulating pump (see 9.2.1.1).
3. Remove the temperature limiter (see 9.2.2.1).
4. Remove the temperature sensor (see 9.2.3.1).
5. Remove the combustion air fan (see 9.2.4.1).
6. Remove the burner, flame monitor and glow pin (see 9.2.5.1).
7. Remove the burner head (see 9.2.6.1).
8. Complete the work on stripped-down components (see 9.1.1).
9.2.7.2 INSTALLATION
1. Install the burner head (see 9.2.6.2).
2. Install the burner, flame monitor and glow pin (see 9.2.5.2).
3. Fit the combustion air fan (see 9.2.4.2).
4. Install the temperature sensor (see 9.2.3.2).
5. Install the temperature limiter (see 9.2.2.2).
6. Install the circulating pump (see 9.2.1.2).
7. Install the heater (see 8.7.1.2).
www.webasto.us 41 Webasto Product N.A., Inc.
Page 48
REPAIR THERMO 90 ST
This page for your notes.
Webasto Product N.A., Inc. 42 www.techwebasto.com
Page 49
THERMO 90 ST PRODUCT INFORMATION
10. PRODUCT INFORMATION
No new or updated information available at this time.
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Page 50
PRODUCT INFORMATION THERMO 90 ST
This page for your notes.
Webasto Product N.A., Inc. 44 www.techwebasto.com
Page 51
THERMO 90 ST WARRANTY
W
ARRANTYCOVERAGE ANDLIMITATIONS
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.
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Org. 03/2008 Rev. 6/2012 P/N LIT1301498A
WEBASTO PRODUCT N.A., INC.
15083 North Road Fenton, MI 48430
Technical Assistance Hotline USA: (800) 860-7866 Canada: (800) 667-8900
www.techwebasto.com www.webasto.us
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