SF-35F Blowing Air but no heat
4-22-2014 I have a SF-35F furnace in my RV trailer. Whenever I turn the thermostat to heat, I get airflow, but no heat. It will blow air for about 4 minutes and then shut off. I can repeat it by turn...
Forum Discussion
The most common problem on the SF series is a bad Hi limit switch. If the Hi limit is stuck open, then the control board will not start the Ignition cycle. Then it shuts off. The Hi limit is the first thing I check and the easiest to access on the inside of the RV. Doug
