Atwood heater lighting but not staying lit"

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Atwood heater lighting but not staying lit"

April 28, 2024, 05:13:33 pm

Ok...Trying to figure out what's going on with my rear furnace in my 99 U295. Woke up yesterday morning with the blower running but not blowing hot air. The startup sequence appears to be happening but heater will not stay lit. When I turn on furnace, blower will come on and do its purge, then propane valve opens, as I can smell it, then igniter starts sparking, heater lights, runs about 3 seconds, then goes out....it does this three times then blower just continues to run... I have a full propane tank and have lit and let all three stove burners burn. It worked fine about a week ago.. I could just order a knew board if I knew that was problem. This coach no longer has a front furnace as the previous owner remodel to residential fridge, eliminated that. Or I would swap to check....any other suggestions to try. P.S. .... We are out on road currently in Arkansas and it is not cold currently. So really not needed right now but would like to get working for future...

Re: Atwood heater lighting but not staying lit"

Reply #1 – April 28, 2024, 05:25:59 pm

Check the gap on the igniter,went thru the same thing once,will try and find what the gap is but I did find it on line.My burner tube
was also badly rusted and needed replacement.

Re: Atwood heater lighting but not staying lit"

Reply #2 – April 28, 2024, 05:34:56 pm

I checked igniter. It sparks and lights the burner. I'm just wondering what would tell the propane valve to shut off after lighting. That appears to be what's happening. Does the sail switch do this? or temperature sensor? Anyway, it's pouring down rain now so my troubleshooting I believe is done for the day. Severe weather warning tonight, great..

Re: Atwood heater lighting but not staying lit"

Reply #3 – April 28, 2024, 05:42:56 pm

Might be a bad Sail Switch.

jk

Re: Atwood heater lighting but not staying lit"

Reply #4 – April 28, 2024, 05:48:04 pm

See the trouble shooting guide, Pg. 43 in manual linked below.

BURNER IGNITES BUT IGNITION SYSTEM "LOCKS OUT" AND TURNS BURNER OFF

https://myrvworks.com/wp-content/uploads/2019/04/Atwood-Furnace-Training-Manual.pdf

Re: Atwood heater lighting but not staying lit"

Reply #5 – April 28, 2024, 06:00:50 pm

Thanks Chuck, that will definitely give me some more things to check. Great manual....

Re: Atwood heater lighting but not staying lit"

Reply #6 – April 28, 2024, 07:26:16 pm

My guess is that the burner screen is rusted out and so the flame is not hitting the igniter sensor probe. That is very common on coaches of that vintage. You can get a new burner on Amazon and also EBay.

Re: Atwood heater lighting but not staying lit"

Reply #7 – April 28, 2024, 07:55:17 pm

Gap is 1/8 inch.

Re: Atwood heater lighting but not staying lit"

Reply #8 – April 28, 2024, 08:08:51 pm

I vote with Red Tractor. I carry a spare screen with me and have replace both front and rear heater screens a few years ago.

Re: Atwood heater lighting but not staying lit"

Reply #9 – April 29, 2024, 12:07:07 pm

Quote from: red tractor – April 28, 2024, 07:26:16 pm

My guess is that the burner screen is rusted out and so the flame is not hitting the igniter sensor probe. That is very common on coaches of that vintage. You can get a new burner on Amazon and also EBay.

Yep .... had the same problem this winter. If the burner tube is rusted (I.e. has holes in it ) the flame won't heat the flame sensor and the control board will shut off the gas valve.
I just replaced both of mine, front heater would shut down and blow cold. I replaced the rear as a precautionary and on examination it was almost bad bad as the front one was so it would have failed soon

Both were original as far as I could tell.

Re: Atwood heater lighting but not staying lit"

Reply #10 – April 29, 2024, 12:11:22 pm

Can't be the sail switch. The sail switch is what triggers both ignitor and gas valve.

Since both were triggered/engaged, the sail switch is working.

Re: Atwood heater lighting but not staying lit"

Reply #11 – April 29, 2024, 07:17:40 pm

BURNER IGNITES BUT IGNITION SYSTEM "LOCKS OUT" AND TURNS BURNER OFF

When I have had this problem with water heaters and furnaces with a thermocouple controlled gas valves either the thermocouple was not placed in the flame properly or it was bad. You can test the thermocouple by placing it in a hot flame and measuring for a small voltage. The current from the thermal-couple hold the gas valve open until the thermostat shuts the gas valve or the flame stops. If the thermocouple is bad replace it, if good replace the valve.

Tim

Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 12, 2025 ...

Atwood heater lighting but not staying lit"

April 28, 2024, 05:13:33 pm

Re: Atwood heater lighting but not staying lit"

Reply #1 – April 28, 2024, 05:25:59 pm

Re: Atwood heater lighting but not staying lit"

Reply #2 – April 28, 2024, 05:34:56 pm

Re: Atwood heater lighting but not staying lit"

Reply #3 – April 28, 2024, 05:42:56 pm

Re: Atwood heater lighting but not staying lit"

Reply #4 – April 28, 2024, 05:48:04 pm

Re: Atwood heater lighting but not staying lit"

Reply #5 – April 28, 2024, 06:00:50 pm

Re: Atwood heater lighting but not staying lit"

Reply #6 – April 28, 2024, 07:26:16 pm

Re: Atwood heater lighting but not staying lit"

Reply #7 – April 28, 2024, 07:55:17 pm

Re: Atwood heater lighting but not staying lit"

Reply #8 – April 28, 2024, 08:08:51 pm

Re: Atwood heater lighting but not staying lit"

Reply #9 – April 29, 2024, 12:07:07 pm

Re: Atwood heater lighting but not staying lit"

Reply #10 – April 29, 2024, 12:11:22 pm

Re: Atwood heater lighting but not staying lit"

Reply #11 – April 29, 2024, 07:17:40 pm

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