Thor Four Winds – Furnace Igniter & Control Board Replacement

I taught myself to handle most RV repairs through a combination of YouTube videos, forum threads, and expensive mistakes. The expensive mistakes were the best teachers. This guide covers what I eventually figured out — without the part where you strip a bolt, order the wrong component, and wait a week for the right one to arrive. When your Thor Four Winds furnace starts clicking endlessly without igniting — or goes completely silent — you’re usually looking at a failed igniter, a dead control board, or both, and when you live in your rig through winter, that’s not a someday problem. A furnace that won’t fire at 2am in 20-degree weather has a way of sharpening your diagnostic skills fast, and after going through this repair the hard way on my own unit, I put together the straightforward process I wish I’d had the first time.

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.

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.

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