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cwj212 · 02-09-2014, 04:03 PM

He Atwood furnace in our 2010 Suncrusier fires up air shuts down after around 5 minutes. The burner does light and some heat does come out of the ducts but the burner shuts down after around 5 minutes. The blower runs for a couple more minutes and finally shuts down. Any thoughts?

jesilvas · 02-09-2014, 04:35 PM

Sounds like it's lighting but never sensing the heat. However, could be low LP pressure too.
Are you comfortable with 12VDC power or LP gas systems and measuring pressures?

cwj212 · 02-09-2014, 05:18 PM

Quote:

Originally Posted by jesilvas

Sounds like it's lighting but never sensing the heat. However, could be low LP pressure too. Are you comfortable with 12VDC power or LP gas systems and measuring pressures?

It does light up because I can feel the hot exhaust at the outlet...till it starts to cool off and shut down. If it is a possible propane pressure issue, it sounds like I need to take it to the dealer.

vsheetz · 02-09-2014, 05:38 PM

Thermocouple? shuts down the gas flow if no flame, goes bad and erroneously shuts down the gas flow.

jesilvas · 02-09-2014, 06:08 PM

In case anyone doesn't know:
T-stat calls for heat.
One way or another (direct from t-stat, from A/C control board, etc.), 12V+ signal gets to furnace control board.
Control board engages fan motor. Fan blows air.
Enough air flow makes sail switch close contacts, control board knows there is enough air flow.
Almost simultaneously, gas valve opens with 12V+, and ignitor relay begans sending electrical pulses to ignitor, creating sparks to light LPG.
Tries for a certain amount of time, usually three times.
If heat is sensed, gas valve keeps receiving 12V+ to stay open, sparking stops.
T-stat turns off signal for heat once heat is achieved, gas valve shuts off LPG, control keeps blowing fan motor to cool off burner chamber.

Problems that can happen with ignition but flame goes out after sparking stops:
Flame not sensed via flame sensor, wire, connections, or control board. Flame bad via bad burner, clogged orifice/flow/burner, low LPG pressure under heavy flow load, clogged burner chamber.

cwj212 · 02-10-2014, 03:41 PM

We took the MH to camping World today to get the furnace looked at. They checked it and couldn't find anything wrong. They said it ran for 20 minutes with no issue. I asked them to check everything one more time. We left it and went back later. Everything checked out ok. It was outside waiting to go home. They did say to take it and keep checking it for a couple days. If no problem they would send me the bill. If acts up again, bring it back. So, I went out to start the furnace one more time before I left. I found the the thermostat was already on gas heat, 50 degrees inside, temp set to 75. Furnace not running. So, back in I went...

They sent out a tech. He shut it off and re-started it. No heat. He then lit the stove and it had a very low flame. It looks like the regulator in the gas line is bad. While replacing the regulator they also found a leak in the gas line. I hope this does the trick. We're planning on leaving for Florida this weekend!