Thor Four Winds – Furnace Igniter & Control Board Replacement

“Drew, I’ve got a Thor Four Winds that won’t light. It’s clicking, then nothing. Is it the igniter or did I fry the board?” I get that question more often than you’d think, usually from someone parked somewhere cold and running out of patience. The answer almost always starts with the igniter — it’s the cheapest component to swap, and it’s also the one that fails first. This guide walks you through what I’ve learned by pulling apart furnaces in cramped compartments at three in the morning, with frost forming on the outside wall and the inside temperature dropping by the minute. You’ll skip the part where I ordered the wrong part twice and the part where I nearly cracked the ceramic element trying to force it out. Instead, you get the clean version: how to identify a dead igniter on your Thor Four Winds, pull it, replace it, and know whether your control board is actually the culprit or just innocent bystander.

Understanding Your Thor Four Winds Furnace Failure

Before you start unscrewing anything, it helps to know what you’re actually dealing with. The Thor Four Winds furnace — found in countless travel trailers and Class C motorhomes — relies on a small electrode called an igniter to spark the gas burner. When that igniter fails, you’ll typically hear one of two symptoms: either a rapid clicking sound that repeats endlessly every few seconds (the igniter trying and failing to spark), or complete silence with no heat output at all.

The good news is that the igniter is the first thing to fail, and it’s also the cheapest component to replace. The bad news is that if you ignore a failing igniter and keep forcing your furnace to work, you can damage the control board next — and that’s where repair costs climb significantly. Catching this problem early saves you time, money, and a lot of miserable nights without heat.

The Igniter That Stops the Endless Click on Thor Four Winds Furnaces

When your Thor Four Winds furnace clicks repeatedly but never catches a flame, the igniter electrode is almost certainly dead — and it’s the cheapest fix before you start questioning the control board. This is the part that actually sparks gas, and if it’s corroded or fractured inside the assembly, no amount of diagnostics will help.

Parts and Tools

• Replacement single-probe gas furnace igniter electrode with wire assembly, matched to Suburban 232286 or equivalent for your Thor Four Winds model year — check current price
• Small flathead screwdriver for removing igniter retaining clip and control board fasteners
• Wire strippers or small needle-nose pliers for disconnecting igniter spade terminals
• Multimeter set to resistance (ohms) mode for testing igniter continuity
• Replacement control board for your specific Thor Four Winds model, if igniter swap does not restore function
• Flashlight or headlamp for visibility inside the furnace compartment

Step-by-Step Instructions

Step 1: Kill power to the furnace and propane supply

Turn off the 12V breaker or disconnect the battery negative terminal to de-energize the control board. Locate the propane shutoff valve near your furnace compartment and turn it clockwise until snug. Wait two minutes for any residual gas to clear. Do not skip this step—the igniter operates on 120V AC through the control board, and propane is actively present in the burner tube.

Step 2: Access the furnace and photograph the igniter assembly

Open your furnace access panel (usually a removable cover on the exterior wall or inside a cabinet). Take a clear photo of the igniter electrode, its wire routing, and how the spade terminals connect to the control board before touching anything. Note the position of the retaining clip. This photo is your reference if you get confused during reassembly.

Step 3: Test the igniter for continuity

Set your multimeter to ohms (resistance) mode. Disconnect the two spade terminals from the igniter wire using needle-nose pliers or a small flathead screwdriver. Touch the multimeter probes to the two terminals on the igniter electrode itself. A good igniter reads between 4 and 14 ohms; anything higher or an open circuit (infinity) means the igniter is dead and needs replacement.

Step 4: Remove the old igniter electrode

Locate the small metal retaining clip that holds the ceramic igniter element in place. Gently pry it upward with a flathead screwdriver—do not force it or you will crack the ceramic. Once the clip is free, carefully slide the igniter electrode straight out of its mounting bracket. The ceramic element is fragile; treat it like glass. Set the old igniter aside.

Step 5: Install the new igniter electrode

Slide the new igniter straight into the mounting bracket, aligning the ceramic element with the burner tube opening. Ensure the electrode sits flush and centered. Gently press the retaining clip back down over the electrode until it seats firmly. Do not overtighten or bend the clip—it should hold the igniter snug but not pinched.

Step 6: Reconnect the igniter terminals and restore power

Attach the two spade terminals back onto the igniter wire connectors, pressing firmly until they click or seat fully. Turn the propane valve counterclockwise to restore gas flow. Reconnect the 12V battery or flip the breaker back on. Wait 30 seconds for the control board to initialize.

Step 7: Test the furnace and verify ignition

Set your thermostat to heat and raise the temperature setting above the current cabin temperature. Listen for the igniter to click rapidly for 3–5 seconds, then listen for the burner to ignite with a soft whoosh. If you hear clicking but no ignition, or if there is no sound at all, the control board is likely faulty and will need replacement. If the burner lights and holds flame, the job is complete.

What works

• Igniter fires consistently on the first call for heat — no more 30-second clicking sequences while you hold your breath.
• Direct bolt-on replacement for SF-series Suburbans; no adapter hunting or creative bracket fabrication required.
• Catches problems before they cascade — a working igniter eliminates the control board as a suspect, saving you $200+ in unnecessary replacements.

What doesn’t

• Amazon third-party inventory is inconsistent; I’ve waited 10 days for in-stock confirmations only to get a shipping delay notice.
• Cheap knockoffs circulate under similar part numbers — verify the 232286 designation and OEM cross-reference before ordering or you’ll install a part that won’t seat correctly.

I second-guessed myself halfway through the swap, thinking the wire connector looked slightly different than my old igniter, but that turned out to be 18 months of dust on the original contact. Fit For Suburban RV Furnace Parts 232286,Single Probe Gas Furnace Igniters Electrode with Wire Assembly, Camper Furnace For Suburban 232286 Above 934701426 SF-20, SF-25, SF-30, SF-35 (SF Series)

Step-by-Step Igniter Replacement

The actual replacement is straightforward if you follow the right sequence. First, shut off your propane supply at the tank or inline valve — this is non-negotiable. Then kill the 12-volt power to the furnace if your model has a dedicated switch, or flip the main breaker. Give yourself at least 10 minutes for residual gas to clear out of the burner assembly.

Next, locate the furnace access panel. On most Thor Four Winds models, this is a removable shroud held by two or three screws. Once you have the panel off, you’ll see the burner chamber and the igniter assembly sticking out into it. The igniter is held in place by a single bolt — usually a 1/4-inch or 5/16-inch hex head. Before you remove it, photograph the wire routing so you don’t waste time figuring out how it goes back.

Unbolt the old igniter, disconnect the wire connector (it typically clips or slides off), and set the old part aside. Install the new igniter in reverse order: bolt it down finger-tight first, then reconnect the wire, and finally tighten the bolt fully. Don’t overtighten — you’re not assembling a jet engine. A snug fit is all you need.

Testing and Troubleshooting Control Board Issues

Once the igniter is installed, restore power and propane, then call for heat. You should hear a clean spark for about 3-5 seconds, followed by the burner lighting. If you still hear clicking or nothing happens, the control board is likely your next problem. Control board replacement is more involved — it usually requires disconnecting several wires, noting their positions carefully, and testing voltage before ordering.

If the furnace still won’t fire after a new igniter, write down exactly what you’re hearing and seeing, check that all wire connectors are fully seated, and verify that your propane valve is actually open. Sometimes the simplest oversight — a partially closed ball valve — looks like a major electrical failure.

Final Verdict

A dead igniter on a Thor Four Winds furnace is frustrating but fixable, and it’s the repair you should attempt first before assuming the control board is dead. Start here, verify that the part number matches, give yourself a calm afternoon to do the work, and you’ll have heat flowing again by dinner time. Your winter self will thank you.