# RV Furnace and Heating System Repair in Chino > OCRV Center repairs forced-air RV propane furnaces in our Yorba Linda shop, from a blower that runs without heat to a furnace that clicks and shuts down. We diagnose the ignition sequence step by step. All work is in shop only. An RV furnace is a sealed-combustion forced-air unit, so it ignites in a strict sequence: the blower spins up, a sail switch confirms airflow, the board sparks the burner, and the flame sensor proves the flame. When the furnace runs the blower but never heats, or lights and then shuts off, the fault is almost always one specific step in that chain, and we test them in order instead of swapping the board first. ## How we trace a no-heat furnace A blower that runs but never ignites usually means the sail switch is not closing, the gas is not reaching the burner, or the circuit board is not sending a spark. A furnace that lights briefly and then shuts down points instead to the flame sensor or a dirty burner, since the board is shutting the gas off because it cannot prove the flame. We walk the ignition sequence to find which step fails. Most RV furnaces are Suburban or Atwood forced-air units, and each has its own quirks in the sail switch, limit switch, and board. We test the airflow switches, the gas valve, the igniter, and the flame sensor against the unit it actually is, then clean the burner and combustion chamber when soot or a clogged orifice is starving the flame. - Blower-runs-but-no-heat and no-ignition diagnosis - Sail switch and limit switch testing - Circuit board, gas valve, and igniter replacement - Flame sensor cleaning and short-cycle correction - Burner, orifice, and combustion chamber cleaning ## Blower, airflow, and safe combustion A furnace that short-cycles or trips on its limit switch is often choked by blocked ducting, a tired blower motor, or a return-air restriction, so we check the airflow path and the blower wheel rather than just resetting the limit. Correct airflow is what keeps the heat exchanger from overheating and tripping the unit offline. Because the furnace is a combustion appliance vented through the sidewall, we inspect the exhaust and the heat exchanger for cracks or soot that could let combustion gases into the coach. A cracked exchanger is a replacement, not a patch, and we flag it as a safety issue rather than returning the unit to service. - Blower motor, bearing, and wheel service - Ducting, return-air, and airflow restriction checks - Heat exchanger inspection for cracks and soot - Sidewall exhaust and combustion-air vent clearing - Thermostat and 12V power supply diagnosis ## Frequently asked questions ### My RV furnace blower runs but no heat comes out, why? The blower runs first to prove airflow, so heat that never follows usually means the sail switch is not closing, the gas is not reaching the burner, or the board is not sparking. We test those steps in sequence to find the one that is failing. ### My furnace lights then shuts off after a few seconds, what is that? That is classic short-cycling on the flame sensor. The board sparks, the burner lights, but the sensor cannot prove the flame, so the board shuts the gas off as a safety step. We clean or replace the sensor and clear the cause. ### Do you check the furnace for unsafe exhaust? Yes. The furnace is a combustion appliance vented through the sidewall, so we inspect the heat exchanger and exhaust for cracks and soot. A cracked exchanger gets replaced, not patched, because it can let combustion gases into the coach. --- Source: https://oc-rv.com/services/rv-furnace-heating-repair/ OCRV Center, 23281 La Palma Ave, Yorba Linda, CA 92887. Phone (949) 799-3387. In shop only; insurance billed direct.