Complete repair guide for the Thor Tranquility – Diesel Heater Glow Plug & Fuel Pump Service. Follow these steps to diagnose and fix the issue yourself.
Parts & Tools You’ll Need
- Webasto / Espar ceramic glow plug
- Diesel heater fuel dosing pump (12V)
- Inline diesel fuel filter
- Diesel heater LCD control panel
- Combustion chamber blower motor
- Intake & exhaust silencer kit
- Diesel fuel line silicone tubing (4mm)
- Digital multimeter (auto-ranging)
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Step-by-Step Repair Guide
Step 1: Diagnose Heater Issues & Prepare
Start by connecting your digital multimeter to the diesel heater’s control panel and check for 12V power supply at the glow plug connector. Turn off all electrical systems, disconnect the negative battery terminal, and allow the heater unit to cool completely before proceeding with any component removal.
Step 2: Remove Old Glow Plug Assembly
Locate the ceramic glow plug on the combustion chamber head and carefully unscrew it using the appropriate socket or wrench, being mindful not to damage the fragile ceramic element. Set aside the old glow plug and inspect the threaded cavity for any carbon buildup or debris, cleaning it gently with a dry brush if necessary.
Step 3: Replace Fuel Dosing Pump Unit
Disconnect the fuel line connector from the old dosing pump and remove the pump’s electrical harness from the control panel. Install the new 12V fuel dosing pump by reversing the removal process, ensuring the fuel inlet line is properly seated and the electrical connector is fully engaged until you hear a click.
Step 4: Install New Ceramic Glow Plug
Screw the new Webasto/Espar ceramic glow plug into the combustion chamber head by hand first to avoid cross-threading, then tighten it firmly with your socket wrench. Reconnect the glow plug electrical connector to the control panel, ensuring the connection is secure and corrosion-free.
Step 5: Service Fuel Lines & Filter
Replace the inline diesel fuel filter by disconnecting both fuel line connections and sliding out the old filter cartridge. Install the new filter in the same orientation, using the fresh 4mm silicone fuel line tubing to reconnect the fuel system and ensure all connections are tight to prevent leaks.
Step 6: Verify Control Panel & Blower
Check that the LCD control panel is free of moisture and cracks, and verify the combustion chamber blower motor spins freely when you manually rotate the fan blade. If either component shows damage or the blower is stuck, replacement may be necessary before proceeding with heater operation.
Step 7: Test Complete Heating System
Reconnect the negative battery terminal and power up the heater using the LCD control panel, allowing the glow plug to warm for 15-20 seconds before the fuel pump begins dosing. Listen for smooth fuel ignition, confirm exhaust air flows freely from the silencer kit, and check all fuel connections for leaks using your multimeter to verify 12V power at critical points.
Recommended Parts
| Part | Link |
|---|---|
| Webasto / Espar ceramic glow plug | View on Amazon |
| Diesel heater fuel dosing pump (12V) | View on Amazon |
| Inline diesel fuel filter | View on Amazon |
| Diesel heater LCD control panel | View on Amazon |
| Combustion chamber blower motor | View on Amazon |
| Intake & exhaust silencer kit | View on Amazon |
| Diesel fuel line silicone tubing (4mm) | View on Amazon |
| Digital multimeter (auto-ranging) | View on Amazon |