furnace works but cuts out at night

[inspectorgf]

Ok my furnice starts and works fine but then sometimes during the night it stops working. If i turn it off and back on it fires back up. I'm sure cutting off at night is just a coincidence because we don't have furnace on during day. So does this sound like a problem with thermostat or with furnace. It is a domectic with digital thermostat

[kz08h5]

Sounds like your furnace doesn't want to work the night shift !!!

I check for obstructions in air inlet and exhaust ports. Insects build nests in there.

[Herk7769]

Originally Posted by kz08h5

Sounds like your furnace doesn't want to work the night shift !!!

I check for obstructions in air inlet and exhaust ports. Insects build nests in there.

Times two. Even a spider web can adjust the mixture to the point where ignition is unreliable. The furnace also has a "3 strikes you're out" circuit. If it fails to light 3 times you must turn the unit off; then back on for it to try again.

There is a long propane line purge between light attempts and if the gas built up it could cause a problem if it did light.

[Herk7769]

What is the battery voltage when you go to bed?

Are you boondocking? The furnace is the largest consumer of propane and battery juice in the camper. At voltages less than 11.5 volts, there may not be enough juice to reliably open the gas solenoid. This equates to a battery voltage monitor indication of "L" or "LOW." It will actually be nearly DEAD when the "F" light (FAIR) goes out.

Boondockers in cold weather almost always have 2 batteries for this reason (and many others).