PRIME TIME AVENGER 27DBS - Furnace Igniter Replacement

PRIME TIME AVENGER 27DBS – Furnace Igniter Replacement

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Complete repair guide for the PRIME TIME AVENGER 27DBS – Furnace Igniter Replacement.

Parts & Tools You’ll Need

Step 1: Diagnose the Furnace Ignition Problem

Start by setting your RV thermostat to heat mode and listening for the furnace blower to engage. If you hear the blower running but smell no gas ignition or see no flame in the combustion chamber after 30 seconds, the igniter is likely faulty. Turn off the furnace immediately and check the 12V power supply at the furnace control board using a multimeter—you should read between 11-13 volts DC. Document whether the blower motor runs independently, as this helps determine if the issue is isolated to the ignition system or affects the entire furnace circuit.

Step 2: Disconnect Power and Remove Access Panels

Turn off the propane supply at your RV’s main tank valve and disconnect the negative battery terminal to eliminate all power sources to the furnace. Remove the lower access panel beneath your furnace using a Phillips head screwdriver—typically four to six fasteners. Locate and photograph the wire harness connections leading to the control board before disconnecting anything, as this reference will prevent wiring errors during reassembly. Allow the furnace to cool for at least 10 minutes if it was recently running, as the combustion chamber and control board can retain significant heat.

Step 3: Remove Old Control Board and Igniter Assembly

Disconnect the wire harness from the Atwood RV Furnace Igniter Board by gently prying the connector clips away from the mating surface—do not pull on the wires themselves. Note the routing of all wires through the furnace housing, as proper cable management prevents heat damage during operation. Remove the two 10-32 machine screws securing the igniter board to the furnace mounting bracket and carefully slide the assembly out toward you. Inspect the old board for burn marks, cracks, or corrosion around the spark electrode connections, which confirms ignition failure.

Step 4: Install New Atwood Igniter Board Assembly

Position the new Atwood RV Furnace Igniter Board into the mounting bracket and align the screw holes, then torque the 10-32 machine screws to 12-15 inch-pounds—do not overtighten or you risk cracking the circuit board. Route the wire harness through the same cable clips and holders used by the original assembly, maintaining clearance from sharp edges and hot surfaces. Verify that the spark electrode protrusion extends approximately 3/16 inch into the combustion chamber burner box by visually inspecting the spark gap. Reconnect the wire harness to the board, ensuring the connector seats fully with an audible click.

Step 5: Replace Sail Switch and High-Limit Reset

Locate the Furnace Sail Switch (flow switch) mounted on the blower intake duct and disconnect its two-wire connector by gently spreading the clip tabs. Remove the single Phillips screw securing the switch bracket to the duct and slide the assembly out. Install the new Furnace Sail Switch in the identical position, torquing its mounting screw to 8-10 inch-pounds, then reconnect its wire harness ensuring proper polarity. Check the sail arm for smooth, unrestricted movement—it should deflect slightly when you apply gentle finger pressure to confirm the mechanical switch contact operates correctly.

Step 6: Reconnect Propane Line and Reassemble Housing

Verify that your main propane isolation valve is still off, then inspect the propane line connection at the furnace inlet for debris before reattaching. Connect the propane line and hand-tighten the 3/8-inch flare fitting, then use a wrench to torque it to 12-15 foot-pounds—check for leaks with soapy water after pressurization. Reinstall all access panels and fasteners, ensuring they’re snug but not over-torqued, as plastic brackets can crack under excessive force. Replace any damaged gasket seals around the access panels to maintain proper furnace draft and combustion air intake.

Step 7: Test Ignition System and Verify Operation

Reconnect the negative battery terminal and open your main propane supply valve fully. Turn the RV thermostat to heat mode and set the temperature 5 degrees above the current cabin temperature, then listen for the blower to engage within 5 seconds. You should hear a subtle spark sound for approximately 3 seconds, followed by propane ignition and steady flame in the combustion chamber—if ignition fails, turn off immediately and recheck all wire connections. Allow the furnace to run for 5-10 minutes while monitoring the cabin temperature rise and checking that hot air flows steadily from all vents without odor.