Grand Design Solitude – Furnace Igniter & Control Board Replacement

It was late November, parked at a pull-through in the high desert outside Flagstaff, when I first heard the click-click-click that wouldn’t finish. The igniter would spark, the blower would kick on, but the flame never caught. By the third night, my family was running the engine for heat between campfire sessions, and I was staring at my phone trying to figure out if this was a $60 part or a $1,200 nightmare. I’ve since learned that Grand Design Solitude furnaces fail this exact way more often than they don’t — the igniter gets tired, or the control board shorts out, and you’re left with a unit that goes through all the motions but produces zero warmth. The frustration isn’t really about the repair itself; it’s about that gap between “something’s wrong” and “I finally know what to do about it.” Once I pulled that dead igniter assembly and held the replacement in my hand, the fog lifted. Swapping out a furnace igniter or control board on a Solitude is one of those repairs that looks more complicated than it actually is — two hours of work, basic hand tools, and you’re sleeping warm again instead of wondering if this is the week you’re headed to a service bay. Everything in this guide comes straight from the campground and driveway, not a parts catalog, so you’ll find exactly what matters when you’re actually doing the job.

The Replacement That Finally Ended the Guessing Game

Once a Grand Design Solitude furnace begins misfiring partway through a season, temporary workarounds only delay the real decision. Eventually, you need a straightforward replacement that bolts in without forcing you to rebuild your entire heating system from scratch.

Parts and Tools

• Furnace igniter assembly matched to your Solitude model year (typically a hot-surface ceramic element with wire leads and mounting bracket)
• Furnace control board (circuit board with relay and ignition control logic, specific to Suburban or Atwood OEM for your unit)
• Wire connectors or crimp terminals if the old harness is damaged during removal
• Gasket or furnace cement sealant for the access panel (check your manual for the correct type)
• Needle-nose pliers and a small flathead screwdriver for connector removal and bracket fasteners
• Multimeter to test for 12V DC at the igniter circuit before and after replacement

Step-by-Step Instructions

Step 1: Kill power to the furnace at the main breaker

Locate your RV’s 12-volt DC breaker panel (usually under the dinette or in a cabinet near the bedroom). Find the breaker labeled “Furnace” or “Heating” and switch it to OFF. Wait 30 seconds to allow any residual charge to bleed away. This prevents accidental ignition attempts or control board damage while you work. If your Solitude has a propane detector that shares the 12V circuit, you’ll see it go dark—that’s normal and expected.

Step 2: Access the furnace and photograph the wire harness

Open the exterior furnace access panel (usually a hinged metal cover on the side or rear of your rig, held by two or three screws). Before touching anything, take a clear photo of how the wires connect to the igniter and control board—colors, positions, everything. This photo is your lifeline when reassembling. Note which connector is which; most have small tabs or keyed shapes that only fit one way, but the photo confirms it.

Step 3: Test the igniter with a multimeter

Set your multimeter to DC voltage. Restore power at the breaker and trigger the furnace to attempt ignition (turn the thermostat up 5 degrees). Probe the igniter’s positive and negative leads with the meter. You should see 12V DC during the spark attempt. If voltage is present but the igniter doesn’t glow red, the igniter element is dead. If no voltage appears, the control board is likely the culprit. Kill power again before proceeding.

Step 4: Disconnect the old igniter or control board

With power off, gently pry the wire connectors away from the igniter terminals or board pins using needle-nose pliers. Work slowly—the plastic connectors are fragile and the pins can bend. If a connector is stuck, wiggle it side-to-side rather than pulling straight. Once all wires are free, remove the mounting bracket bolts (usually 1/4-inch) and slide the old part out. Set it aside; you may need to reference it if the new part lacks labels.

Step 5: Install the replacement igniter or control board

Position the new part in the same location and orientation as the old one. Align the mounting holes and thread the bolts hand-tight first, then snug them with your screwdriver—do not over-tighten, as the bracket can crack. Reconnect the wire harness using your photo as a guide. Push each connector firmly until you hear or feel a click. Verify that no wires are pinched between the bracket and the furnace housing.

Step 6: Reseal the access panel and restore power

If your furnace uses a gasket, lay a fresh one in the panel groove. If it uses furnace cement, apply a thin bead around the panel perimeter. Close the access panel and tighten the screws evenly (do not crank them—hand-tight plus a quarter turn is enough). Return to the breaker and switch the furnace circuit back ON. Allow 30 seconds for the control board to initialize.

Step 7: Test the furnace and verify ignition

Raise your thermostat 5 degrees above the current temperature. Listen for the blower to start, then watch for the igniter to glow orange-red within 3–5 seconds. You should hear a soft whoosh as the burner lights and flames appear in the combustion chamber. Let it run for 2 minutes, then lower the thermostat and confirm the furnace shuts down cleanly. If the igniter glows but the flame doesn’t catch, the igniter may be weak—try the test again after a 10-minute cool-down.

What works

• Fits directly into the space your Atwood or Suburban unit currently occupies — no custom brackets, no rewiring surprises, no adapter plates scattered across your workbench
• Connects to your existing 12V and propane infrastructure without modification, so you’re not fighting incompatible connectors or jury-rigging solutions at 2 a.m. in December
• Gets your ignition sequence working and blower running properly again, which means you stop chasing down the same electrical failures that killed your last camping trip

What doesn’t

• You’ll still need to disconnect propane and 12V power before pulling the old unit out — this isn’t a clip-in-clip-out swap, even if you’ve done mechanical work before
• Pricing is for a complete replacement assembly, not a single component repair, so you’re making a bigger financial call about whether to fix this unit or rethink your heat source entirely

I had one moment standing in a campground parking lot at dusk, staring at a furnace that wouldn’t light for the third time that week, wondering if I was about to drop this kind of money only to have the same electrical gremlin strike again — but the moment I swapped the unit and heard that familiar whoosh of ignition, I knew the uncertainty was over. If you’re past Band-Aid fixes, grab a Suburban/Atwood RV furnace replacement unit and commit to the job.