What Does RV Furnace Repair Cost? Sail Switch, Control Board, Blower, or a Whole New Furnace

The first cold night of fall is when most RV owners find out their furnace quit sometime last spring. The good news is that RV furnaces are simple machines, and most of what goes wrong with them is a part that costs less than a tank of propane. The bad news is that the labor is rarely about the part — it is about getting to it. This guide covers what each common furnace repair actually costs in 2026, why two quotes for the same part can be $300 apart, and the one finding that should end the repair conversation.

Why the same $40 part can be a $150 or a $450 repair

Nearly every RV furnace on the road is a Suburban (SF series) or an older Atwood/Dometic Hydro Flame. Both are ducted forced-air units that burn propane in a sealed combustion chamber, pull outside air in and push exhaust out through the same exterior door, and run a 12-volt blower to move heat through the coach.

Some repairs happen from the outside access door with the furnace in place. Others require sliding the whole unit out of its cabinet, which means disconnecting the gas line, the 12-volt feed, the thermostat wires, and the ducts, then pulling it through the exterior opening. In some floorplans the tech also has to open an interior panel or a drawer bank to free the ducts.

That is the whole cost story. A part reachable through the door is a short visit. A part that requires pulling the furnace adds one to three hours of labor before anyone touches the failed component — plus a gas leak test on reinstall, which is not optional.

In 2026, expect $125 to $225 for a mobile service call (most techs credit it toward the repair) and $125 to $190 an hour for labor.

The common repairs and what they run

These are the failures that fill a tech's fall calendar, roughly from most to least common:

• Sail switch — a small paddle that the blower's airflow pushes closed to prove the fan is moving enough air before the burner is allowed to light. Lint, pet hair, or a weak blower keeps it from closing, and the furnace blows cold. Part $20 to $45. On many Suburbans it is reachable from the outside; on others the furnace comes out. $120 to $350 total.
• Ignition control board — the brain that runs the purge, spark, and flame sense sequence. Low battery voltage and voltage spikes kill them. Part $90 to $200, usually reachable without pulling the unit. $200 to $400.
• Igniter electrode — a sooted or cracked spark electrode means clicking with no flame. Part $20 to $50. $120 to $250.
• Limit switches — the high-limit and any secondary limit shut the burner down if the chamber overheats. A failed one looks like a furnace that lights and drops out. Part $15 to $40, but a limit that tripped from overheating points at blocked ducts or a weak blower, and a good tech finds out which. $120 to $300.
• Gas valve — a valve that won't open or won't hold. Part $90 to $200. $250 to $500.
• Blower motor — squealing, grinding, or a fan that won't spin. The motor runs both the circulating fan and the combustion air wheel, and on most units the furnace comes out to replace it. Part $120 to $260. $350 to $750.
• Thermostat — a basic analog or digital wall stat is $40 to $120; a multi-zone control panel tied into the A/C system runs $150 to $350 plus programming. $100 to $450.
• Crushed or disconnected ducts — the furnace heats fine but one end of the coach stays cold, or the limit keeps tripping. Rerouting or replacing a flattened duct under a bed or a slide is $100 to $350, depending on how much cabinetry comes apart.

If you have already worked through the sequence in our guide to an RV furnace that blows cold air, you have probably narrowed it to one of these, which makes the tech's visit shorter.

The finding that ends the repair talk: the combustion chamber

The heat exchanger, or combustion chamber, is the sealed box where the flame burns. It is what keeps exhaust — including carbon monoxide — on the outside of the airstream that blows into your coach. When a tech finds it cracked, rusted through, or burned open, the furnace is done. No one should weld or patch it.

The signs that point there:

• Soot around the exhaust vent on the outside door, or inside at the registers.
• A yellow, lazy, or lifting flame instead of a steady blue one.
• The CO alarm going off while the furnace runs.
• Visible rust-through or holes when the unit is pulled.

Any of those, and the conversation turns to a new furnace. In 2026:

• New Suburban SF series, 20,000 to 42,000 BTU: $700 to $1,150 for the unit.
• Install: $400 to $900 for a same-size swap — remove the old unit, set the new one, reconnect gas, 12 volts, thermostat, and ducts, then leak test and verify combustion.
• Adapting a different brand or size to an existing opening: add $150 to $500 for a conversion door, cabinet trim, or duct changes.

Realistic total: $1,200 to $2,300, installed.

Repair, replace, or live with space heaters?

Four questions settle it:

How old is it? A well-kept RV furnace often lasts 15 to 20 years. A furnace approaching that range that needs a blower motor and a board is a candidate for replacement rather than two more repairs.

Is the repair more than half the price of a new unit? If you are looking at $700 of motor and labor on a 17-year-old furnace, a $1,500 installed replacement resets the clock and the warranty.

Are parts still easy to get? Suburban parts are widely stocked. Parts for older Atwood and Hydro Flame furnaces are getting slower to source in some areas — ask the tech whether the part is on a shelf or on backorder before you commit to a repair that could leave you without heat for weeks.

How do you camp? Owners on full hookups all winter sometimes lean on electric heat and keep the furnace as backup. That works — but a furnace is what keeps your tank bays and plumbing above freezing in many coaches, since ducts often run through the underbelly. A space heater in the living area does not do that job. If you camp anywhere that freezes, the furnace is not optional equipment.

When to call a pro

There is real owner work here: check battery voltage at the furnace (anything under about 12 volts causes a long list of fake failures), clear the exterior vent of nests and wasp mud, make sure every register is open, and confirm the propane tank is not just empty.

Past that, the line is clear. Anything that opens the gas train — the valve, the burner, the orifice, a fitting — is licensed work, and it ends with a leak test and a combustion check. Pulling the furnace means breaking and remaking a gas connection. And any CO alarm, any soot, or any smell of exhaust inside the coach means shutting the furnace off, ventilating, and leaving it off until a tech has looked at the combustion chamber.

Cold-weather markets book up fast in October. If you're heading into the high country, RV furnace repair in Denver and mobile RV techs in Flagstaff are good places to start, or use the RV repair hub for the rest of the map.

FAQ

Why does my RV furnace cost more to fix than the part costs? Because many parts, especially the blower motor and some sail switches, can only be reached by pulling the furnace from its cabinet — one to three hours of labor plus a gas leak test before the part is even changed.

Can a cracked RV furnace heat exchanger be repaired? No. A breached combustion chamber can leak carbon monoxide into the coach. The safe repair is a new furnace.

How long does an RV furnace last? Typically 15 to 20 years with annual cleaning and good battery voltage. Boards and blower motors often fail sooner and are replaceable.

Is it worth getting the furnace serviced before winter? Yes. A fall cleaning and inspection usually runs $150 to $300, and it catches nests, lint on the sail switch, and weak blower bearings before they strand you on a cold night.

Don't wait for the first freeze to find out. Call 833-FIXED-RV (1-833-349-3378) — one call, answered live 24/7, and we connect you to a vetted, licensed, insured local tech who can diagnose it in person. It's free for RV owners, and the work is backed by our $2,500 Workmanship Guarantee.