About 75% of furnace calls finish as a single-component swap - a failed ignition control board, a stuck sail switch, or a corroded flame sensor. RV furnaces are simple, sealed-combustion gas appliances bolted into a coach that vibrates, sits unused for months, and cycles between humid Florida summers and sub-freezing Idaho winters.
The result is predictable: sail switches that gum up while the rig sat through hurricane season, ignition boards that fry from a marginal 12V source, and blower motors that develop bearing slop after 8-10 years. We carry Suburban and Atwood ignition boards, sail switches, limit switches, flame sensors, and the most common Dometic blower motors on every truck so most calls finish in one visit.
Signs you need an RV furnace repair
Four patterns cover almost every furnace call we run. If your unit is doing one of these, the diagnosis is usually quick:
1. Blower runs, no ignition
Thermostat calls for heat, blower spins up, you hear a click - then nothing. Locks out after 30-60 seconds. Almost always a sail switch that won't make contact, a corroded flame sensor, or a failed ignition board. $185-$385 fix on most Suburban NT and Atwood units.
2. Lights but flame drops
Burner ignites cleanly, you feel heat for 20-30 seconds, then the flame cuts and the blower keeps running. Classic flame-rectification failure - a dirty or cracked flame sensor not proving flame to the board. Clean or replace - $135-$245.
3. Weak or no airflow
Furnace lights, but warm air barely moves through the registers. Tired blower motor with worn bearings or a packed squirrel cage. Could also be a collapsed duct boot. $285-$485 motor swap.
4. Cycles on overheat
Furnace runs 5-10 minutes, then shuts on a high-limit trip and won't restart for 10-20 minutes. Limit switch is opening because airflow is restricted - cold-air return blocked, blower wheel dirty, or duct boot collapsed. Test, clean, replace as needed.
What we fix - mobile RV furnace service
What's included in a mobile furnace service call
Every call starts with a 15-minute diagnostic sequence. We pull the access panel, check 12V supply at the board under load, meter the sail switch and limit switch in their actual operating positions (not just resting), inspect the flame sensor for soot or oxidation, and confirm gas pressure at the burner orifice. From there it's either a single-part swap, a clean-and-test, or a board replacement.
For ignition board replacements, the sequence is: power off at the 12V breaker, photograph the existing wiring, pull the old board, transfer connections to the new OEM-spec replacement, restore power, run five consecutive ignition cycles to verify the sail switch holds and the flame sensor reads stable, then check exhaust draft for proper combustion air flow. We finish with a CO sniff at the registers as a safety check.
Repair vs replace - quick decision guide
| Symptom | Repair Likely | Replace Likely |
|---|---|---|
| Blower runs, no ignition | Sail switch / board / flame sensor - $185-$385 | If gas valve has failed |
| Lights then drops flame | Flame sensor clean / swap - $135-$245 | Almost never |
| Weak airflow | Blower motor + clean - $285-$485 | If chassis is corroded |
| Cycles on high-limit | Clean blower wheel + duct - $185-$285 | If heat exchanger is cracked |
| No 12V at thermostat | Wiring / fuse - $145-$225 | N/A |
| Heat exchanger crack | Never - safety risk | Full replacement - $1,250-$1,950 |
| Rusted-through case | Never - airflow integrity gone | Full replacement - $1,250-$1,950 |
RV furnace repair pricing
Flat-rate, written quote at your site before any work starts. No hourly creep, no diagnostic surcharge.
| Service | Parts / Brand | On-Site Time | Flat-Rate Range |
|---|---|---|---|
| Ignition board replacement | Suburban NT / Atwood Hydro Flame OEM | 1.5-2.5 hours | $285 - $485 |
| Sail switch repair / replace | OEM Suburban / Atwood | 1 hour | $185 - $285 |
| Limit switch test + replace | OEM | 1 hour | $165 - $245 |
| Flame sensor clean | OEM rod | 45 min | $135 flat |
| Blower motor replacement | OEM Suburban / Atwood / Dometic | 2-3 hours | $385 - $585 |
| Gas valve replacement | OEM Suburban / Atwood | 1.5-2 hours | $345 - $545 |
| Burner orifice clean & tune | OEM brass orifice | 1 hour | $145 flat |
| Full annual service | Clean, test, ignition cycle x5 | 1.5 hours | $185 flat |
| Full furnace replacement | Suburban NT-30SP / Atwood AFMD | 4-6 hours | $1,250 - $1,950 |
Flat rate before we roll
A1 RV Repair quotes a phone range before scheduling, then writes you an exact quote at your site before turning a wrench. No hourly creep, no after-the-fact "while we were in there," no diagnostic surcharge.
Furnace brands we service
We carry parts for and service every major RV furnace brand. Most rigs we see run Suburban or Atwood (now Dometic) - the differences in diagnosis are small but matter for parts ordering.
- Suburban - NT-12SP, NT-16SP, NT-20SP, NT-30SP, NT-34SP, NT-40SP gas furnaces
- Atwood / Dometic - AFMD, Hydro Flame 8500/8900 series
- Dometic - DFMD direct-replacement units, electric supplementary heat
- Truma - VarioHeat Comfort and AquaGo combi units (premium)
- Coleman-Mach - rooftop heat-pump combo units (we service the heating side here)
Warranty - what's covered after we repair your furnace
A1 backs every furnace repair with a 90-day workmanship warranty. If a board or motor we installed fails inside that window, we replace it free including the trip charge. Parts carry separate manufacturer warranties (Suburban and Dometic typically run 1 year on electronic components, 2 years on the unit body).
We register part serial numbers in your name at the time of install. The 90-day window does not cover damage from a separate failure - if a weak coach battery is causing repeat board failures, we diagnose that before the third board goes in. Cracked heat exchangers are never something we repair; they are a CO safety issue and require unit replacement.