Have fire but no heat. Atwood 8531

[JayLow]

Good morning... I purchased my TT (2007 Jay Feather 31T) back in October of this year and the furnace worked very well the first time that it was used. I ran out of propane during that first night and refilled both 30 lb. bottles and reconnected. When I turn on the furnace at the thermostat the blower initiates, the propane fires but the air temperature coming out of the ducts/vents is not hot like it was the first night? The hot water heater and stove appear to be working fine which rules out an issue with LP gas flow? The furnace is located below the entertainment center and I removed the exterior panel cover to look for any obstructions (nests, insects, etc.) but it appears to be clean. Any ideas?

[shadester]

Are you sure the burner is lighting? Have you tried turning it off and on a couple times. If you blower is pushing air I'd say the burner is not staying lit for some reason. Do you actually see fire or hear ignition?

[JayLow]

Yes, I'm certain that the burner is lighting... The air is warm just not hot like it was before. The vent closest to the furnace is fairly warm but by the time the air makes it to the opposite end of the TT it is cold...

[shadester]

Only thing I can think of is the burner is not staying continously on till it reaches desired temp since you said the vent closest is fairly warm. Like a faulty thermostat or high limit or such. Last time I had a similar problem it was a bad high limit switch in the rear of the the furnance working only at times.

[JayLow]

I'm thinking that I will replace the LP regulator just for good measure. From what I have read on the Atwood site, insufficient heat is associated with gas pressure or air flow restriction. Just thought I would check to see if anybody else had any experience with this issue... Thank you for your comments, shadester.

[bigmeaux12]

When my last rv did this same thing it was the circuit board. How that's not your problem.
Good luck

TV- 2015 CHEVY 2500 DURAMAX
TT- 2015 JAYCO EAGLE 314BHDS

[RVhiker]

I think your heater symptoms could be caused by one or more ducts being loose or disconnected, either at the heater or further downstream.

[Vaquero]

What felt hot in October, might not feel as hot in last weekend's temperatures.

[DanNJanice]

It is critical that you understand your failure mode in order to troubleshoot your issue. Failing to do so will make you chase your tail until you do.
The first question is, does the flame shut off...ever? For example, if your problem is caused by a faulty high limit or sail switch, then I would expect the main burner to turn off and the furnace would go into lockout.
If you are positive your burner is staying on, but the temperature is not as it should be coming out of the ducts, then I would suspect a restriction of propane flow (spiders love those little ports) or a disconnected duct somewhere.