Furnace / AC problem?

Last year in Colorado, and very cool nights, our heater quit coming on. I can't remember if we heard the click, but seems like we could. Anyway the board was bad and had to have a new one installed. I believe are is a Surburban. heater. Good luck. I had to find a mobile unit to come and repair. Course the part had to be ordered. Get a portable ceramic heater and you should be fine.

Our 120v heater does ok for now. I'll try and replace the thermostat, its a cheap thing to replace and could use an upgrade anyway.

Battery low? The furnace fan runs on the 12V supply.

I've read that sometimes there is some type of interlink between the furnace and the AC. In at least one situation I'm aware of the owner removed the AC shroud and found some loose wires. A bit of electrical tape tape later and both furnace & AC were working.

I replaced the thermostat in my 5er and discovered that the problem was actually NOT the thermostat. We had typical thermostat problems too, like staying off too long, not shutting off at the set temperature, etc. I have since learned that for most 5er's, the furnace is designed to run off 12 v batteries, so they are much more sensitive to workload and maintenance than house furnaces. Sometimes little things like dust buildup or debris in the unit can cause it to lock up. If your problems are not fixed when you replace the thermostat, I would start by doing very extensive cleaning of the unit/motor and see if that makes a difference.

Well, replaced the thermostat... no change.

I had previously checked voltage at the batteries and at the furnace. 13.1v, so I'm good there.

Pulled the furnace today, checked all connections, checked the squirrel cage which spun freely. Everything was spotless, so cleaning wasnt an issue. Propane flow is fine as well.

Since the AC works fine, I'm thinking it must be the controller board on the furnace.

Supply 12 volts to the blower by its self, it should turn on the blower. Sounds like it's the control board which is an easy but pricey fix $125.00-150.00 if you do it yourself.