Furnace question

[FWR]

I started my forced air Atwood furnace at 4PM tonight in my yard preparing to go out tomorrow. The interior temp was 0. It took 2.5 hours to get to 50 and it was set at 60.

The furnace would fire and stay on for a couple of min, the burner would stop for a few seconds but fan would stay on. It would then fire again and the burner would stay on for a few seconds and then turn off. This continued for 2.5 hrs.

I have 2 30lb tanks, I turned one tank on very slowly, the regulator was clear of snow, the furnace vent was clear and sealed during storage, my tanks are full, my battery is charged and I turned on my stove burners for 10 min and they work great.

Should it take 2.5 hours to raise a 6.5x12 house 50 degrees?

A month ago I fired it up when it was 20 degrees out and it took 20 min and it was 65.

Thoughts?

[mysnopro]

Sounds like the cirut board is bad. My camper did that. Fan ran too long and cooled it down before it re fired.

[Dogzlife000]

Limit switch failure or a partially plugged combustion chamber (mouse nest?).

Also, just an FYI. If this is a direct spark model, when it trips out, the circuit board should emit a flashing red light? Count the flashes. I don't have a copy of the manual with me, but Atwood could tell you the issue based on the number of flashes.

[Husker24]

I had a very similar problem with my Atwood recently. It would try 3 times to light and then lock out until I turned it off and on. Eventually it would light but wouldn't put out much heat, took an hour to get from 0 to 40. When it would fail to light I determined it may be something related to the gas because the sequence of events leading up to the actual flame seemed normal and it didn't appear like anything was plugged. I changed the regulator because it was an easy thing to try, the furnace has been working since. I don't know if this would help but seemed to work in my case.

[FWR]

Update..

I changed my dual regulator to a single reg low pressure rated at 11 W.C. This is what Atwood recommends. It has been running and cycling like it should since 9 this morning.

It took 12 min to warm up from 8 to 70.

I hope this does the trick. A little more of a pain to change tanks but I will deal with it as long as it works.

Thank you all replies and suggestions.