If the furnace in your RV is not sufficiently heating or not working at all, there are a few troubleshooting tips you can perform. The first thing to do when RV furnace troubleshooting is to take off the cover and get a good look inside the furnace area. Look for anything out of place, debris or anything that could be blocking the exhaust. Also look to verify that the intake is open and ventilated.
When RV furnace troubleshooting put on a pair of safety goggles and blow out any dust, debris and rust from the furnace assembly using pressurized air. Clean off the grate, ensure it is nice and clean and there is nothing covering the front of it. While cleaning this area out, you may have to get inside the unit manually to clean out stubborn objects that did not come out with the pressurized air. RV furnace troubleshooting may also be necessary when a spider has spun its web inside the furnace area.
Your next RV furnace troubleshooting is to verify that there is 10.5 volts of battery power coming into the unit. Anything under 10.5 will result in the fan operating but just blowing cold air as the gas valves will not open. Next the control panel at the distribution center inside the RV to ensure there is power coming into the RV and the 12-volt automotive fuse is not blown.
Most RV furnaces are controlled by a thermostat on the wall. With road vibration and temperature changes inside the RV, the thermostat could be damaged. The last thing to check is the corrugated tubing that delivers the heat from the furnace to the vents. If they are kinked or bent, it will not allow proper air flow.