Coachmen Galleria – Diesel Heater Glow Plug & Fuel Pump Service

Complete repair guide for the Coachmen Galleria – Diesel Heater Glow Plug & Fuel Pump Service. Follow these steps to diagnose and fix the issue yourself.

Parts & Tools You’ll Need

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Step-by-Step Repair Guide

Step 1: Diagnose Heating System Failure

Start by connecting your digital multimeter to the diesel heater’s 12V power supply to verify adequate voltage is reaching the unit; low or no readings indicate a power supply issue rather than a heater component failure. Next, visually inspect the glow plug connector and fuel pump wiring for corrosion, loose connections, or damaged insulation, as these are common failure points in Class B vans experiencing heating problems.

Step 2: Disconnect Battery and Access Heater

Disconnect the negative terminal of your RV’s auxiliary battery to prevent accidental electrical discharge while working on the heating system. Locate your Webasto or Espar diesel heater unit (typically mounted beneath the floor or in the engine bay of your Coachmen Galleria) and remove any access panels or trim pieces necessary to reach the glow plug and fuel pump components.

Step 3: Replace Ceramic Glow Plug Assembly

Disconnect the electrical connector from the old glow plug and carefully unscrew it from the combustion chamber using the appropriate socket, being cautious not to damage the heating element threads. Install the new ceramic glow plug by reversing the process, ensuring you achieve a snug fit without over-tightening, then reconnect the electrical connector securely.

Step 4: Install New Fuel Dosing Pump

Disconnect the fuel inlet and outlet lines from the old 12V fuel dosing pump, capturing any residual diesel in a small container to prevent spills. Position the new pump in the mounting bracket, reattach both fuel lines with fresh silicone tubing if the old lines show cracks or deterioration, and secure the pump with its retaining hardware.

Step 5: Replace Inline Diesel Fuel Filter

Locate the inline diesel fuel filter in the fuel supply line between the main tank and the heater unit, then carefully disconnect both ends of the filter housing. Install the replacement filter with the flow direction arrow pointing toward the heater, use fresh 4mm silicone fuel line tubing to reconnect both sides, and ensure all connections are hand-tight with no leaks visible.

Step 6: Update LCD Control Panel Settings

If your diesel heater’s LCD control panel is showing error codes or displaying incorrectly, power it down completely for 30 seconds before restarting to reset the system. Access the heater’s menu settings through the control panel to verify that the ignition sequence timing and fuel pump runtime parameters match your heater model’s specifications found in the installation manual.

Step 7: Test Heater System Operation

Reconnect your auxiliary battery, power on the diesel heater, and monitor the LCD control panel as the system cycles through its startup sequence—you should hear the combustion chamber blower engage followed by the fuel pump priming within 10-15 seconds. Allow the heater to run for at least 5 minutes while checking for proper heat output and listening for any unusual grinding or squealing noises that would indicate improper glow plug or pump installation.

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