New Horizons – Furnace Igniter & Control Board Replacement

Drew Callahan here, and as I sit with a New Horizons furnace control board in my hand — the same one I pulled from a rig last week — I can’t help but notice the cracked solder joints on the back. It’s a classic case. This board has endured years of freeze-thaw cycles from campgrounds stretching from Colorado to Canada. Somewhere around the fourth or fifth year, the thermal stress took its toll, and the circuitry gave out. The owner had been observing that frustrating spark-click-shut-off sequence for two weeks, figuring it would hold until spring. Spoiler alert: it didn’t. This is the kind of repair that, if caught early, can cost about $90 in parts and an afternoon of your time. Wait until you’re shivering at 9,000 feet in January, and it will set you back $850 plus a service call. I replace the igniter and control board on a New Horizons furnace more than anything else, and they fail in familiar ways if you know what to listen for — whether it’s a spark that fires but doesn’t ignite the burner or an endless clicking that drains your propane. I’ve documented the exact steps I take on-site, so you can either tackle this yourself or ensure your technician gets it right.

The Control Board That Saved Me From a $2K Emergency Call

When your New Horizons furnace sparks but won’t ignite, it’s often the control board that has silently failed while the igniter does its job just fine. I learned this firsthand, sitting in a campground at 2 AM with a dead furnace, realizing I had ignored the warning signs for weeks. After logging over 80,000 miles across North America in three different rigs, I’ve encountered a lot of furnace issues, and this one is all too common.

Parts and Tools

• Replacement furnace circuit board / control board matched to your New Horizons furnace model number — check current price
• Replacement furnace igniter (hot surface igniter) for your specific New Horizons model
• Small Phillips and flathead screwdrivers for removing panel screws and connector clips
• Needle-nose pliers for disconnecting wire terminals and spring clips
• Flashlight or headlamp to see inside the furnace cabinet
• Phone or camera to photograph wire connections and terminal positions before disconnecting

Step-by-Step Instructions

Step 1: Kill the furnace power at the breaker

Locate your RV’s 12V DC breaker panel and switch off the furnace circuit. Wait 30 seconds to allow any residual power to drain. This prevents accidental ignition or electrical shock while you work. If you’re unsure which breaker controls the furnace, turn it off and try the thermostat—no clicking sound means you’ve got the right one. Do not proceed until you’re certain power is cut.

Step 2: Access the furnace and photograph the wiring

Open your furnace access panel (usually located in a cabinet or under a floor vent). Take clear photos of every wire connection to the control board and igniter before touching anything. Note the wire colors, terminal positions, and how connectors sit. This photo becomes your reassembly map. Zoom in on any connectors that are hard to see—you’ll thank yourself later when you’re reinstalling.

Step 3: Disconnect the old control board

Gently pull each wire connector straight away from the board terminals. Do not yank or twist; connectors can break. Once all wires are free, remove the screws holding the board to its mounting bracket or the furnace frame. Lift the board out carefully. Set it aside—you may need to reference it if a wire color is unclear during reinstallation.

Step 4: Remove the old igniter

The igniter is usually a ceramic or metal rod held by one or two screws or a clip near the burner assembly. Disconnect its wire connector first. Then unscrew or unclip the igniter from its mount. Inspect the old igniter for cracks, discoloration, or a broken tip—these confirm it failed. Do not touch the new igniter’s heating element with bare hands; oils can shorten its life.

Step 5: Install the new igniter

Position the new igniter in the same location and orientation as the old one. Secure it with the original screws or clip, tightening firmly but not over-tight—you want it snug, not stripped. Reconnect the igniter wire to its terminal. Double-check that the igniter sits at the correct distance from the burner (usually 1/4 inch to 1/2 inch); refer to your furnace manual if unsure.

Step 6: Install the new control board

Position the new board on its mounting bracket or frame using the original screw holes. Screw it down securely. Now reconnect each wire to its terminal, using your photos as a guide. Match wire colors and terminal positions exactly—a single misplaced wire will prevent ignition or cause a safety shutdown. Take your time here; this is where most mistakes happen.

Step 7: Restore power and test the furnace

Switch the furnace breaker back on. Set your thermostat to heat and listen for the spark-click sequence. You should hear a rapid clicking for 3–5 seconds, followed by a soft whoosh as the burner ignites. The igniter should glow orange-red just before ignition. If you hear only clicking with no ignition, turn off the furnace immediately and recheck your wire connections against your photos. If it ignites cleanly, let it run for 10 minutes and feel for warm air at the vents.

What Works

• Direct replacement for Atwood/Suburban units — no adapter kits or rewiring needed, just swap and test
• Catches the igniter spark but won’t release propane to the burner (the classic symptom) — diagnosing this yourself with a multimeter costs you 20 minutes instead of a $400 service call
• Affordable enough that replacing it as preventive maintenance before a full-unit failure actually makes financial sense

What Doesn’t

• Installation requires killing the propane supply and confirming the furnace powers on — if you’re not comfortable working with gas appliances, this one belongs on a technician’s bench
• Doesn’t solve igniter failures or sail switch issues — you still need to know which component failed before you order, or you’ll end up with parts you don’t need

I almost ordered an entirely new furnace unit before taking the time to test the control board with my multimeter, discovering zero continuity on the relay. The furnace circuit board / control board costs a fraction of that, and three seasons later, I haven’t looked back.

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