Atwood Furnace starts and then stops quickly - sounds water logged

[ependydad]

We were gone all day today with the HVAC system off. We went to start the furnace; the fan would run for a bit and then would stop until we cycled the thermostat off and back on.

I first checked propane out at the change over valve and it’s showing green. I then checked the stove and was able to run all 3 burners for a bit.

I went outside to see if I could see or hear anything funky. It’s late so I didn’t take anything apart and can’t see anything. But I could hear it and it literally sounds water logged.

https://www.youtube.com/watch?v=3X4_RXldhA0

I can honestly say I’ve never intentionally listened to my furnace ignite before, so maybe this is normal.

The outside temperature is about 60F. Inside temp says 67F and I’ve set it to 75F. It has rained for almost 24 hours straight- very hard at times. We HAVE used the furnace successfully before for hours at a time.

The 12v fuse seems OK. The LED light does not indicate a problem (though I know they’re unreliable). I pulled the fuse and the furnace doesn’t even attempt to start.

The furnace IS under the edge of a slide out’s slide topper rail that dumps runoff water directly onto it.

Any thoughts?

[ependydad]

I opened it up. There’s definitely water inside there but I don’t have an obvious indicator of how it’s getting in.

I opened the basement’s rear wall and didn’t see signs of water down there nor on top of the furnace itself.

https://www.youtube.com/watch?v=vy8I4Pj4Y3w

[Decon Blue]

Just a thought, if I knew in advance that water dumped off slide right in to it , why did you not address it and make a deflector of some sort ? I’d start with the igniter and see if it is sparking, if not take a long lighter like you use to light your outdoor charcoal grill and try lighting furnace in place of spark igniter. If it lights it might dry out the wet situation you got. I’d suppect the board is toast though. Hopefully your under warranty.

[ependydad]

Originally Posted by Decon Blue

Just a thought, if I knew in advance that water dumped off slide right in to it , why did you not address it and make a deflector of some sort?

My intention was to add a gutter to the slide topper rail. I only saw this as a cosmetic issue with leaving a mess on the camper’s wall. I didn’t foresee it somehow water logging the water heater. Either as a warranty item if the rail was put there by Prime Time or as something to deal with the dealer who installed the toppers.

I’d start with the igniter and see if it is sparking, if not take a long lighter like you use to light your outdoor charcoal grill and try lighting furnace in place of spark igniter. If it lights it might dry out the wet situation you got. I’d suppect the board is toast though. Hopefully your under warranty.

The board itself looked dry, which is amazing given the amount of water I saw in there. It still reacts to the thermostat.

I’ll take a look at the igniter tomorrow when I have some free time next.

[ependydad]

Camper is definitely under warranty. I’ve only owned it for 4-5 weeks.

[heavynlori]

Are you on FB page
Primetime RV Owners Group

There have been previous posts about this issue on other PT units

[ependydad]

Originally Posted by heavynlori

Are you on FB page
Primetime RV Owners Group

There have been previous posts about this issue on other PT units

I’m not, but I’ll go looking for it. Thanks!

[sasems]

One of the things that fails on this furnace is the sail switch that is mounted along side the fan. This fan provides circulation air and forced air for the fire box. The switch allows the ignition system to start once there is sufficient air flow to "close" the circuit and once the system shuts down this switch resets. This switch can cause the no ignition fault and can cause the system to not come on if the switch remains "closed" after shutdown. Water in that micro switch may be the culprit. It's been a while since I had my furnace apart I can't remember where the igniter is located. Mine is a flat installation Vs your vertical so, the igniter in the fire box may be compromised by the water as well. My sail switch failed from corrosion so, I keep an extre and do the annual inspection/maintenance as recommended by Attwood.

[5picker]

How did you make out Doug?

[ependydad]

Mobile tech is finally looking at this. Ironic as it’s 90-degrees out there.

He took the control board with him last week to test it. He said it failed once but then tested fine 3 times.

He replaced the ignitor and that didn’t fix the issue.

He pulled the burner tube and it was rusted all to heck.

He’s getting a new control board now.

We’ll see how it goes.

[ependydad]

The new control board fixed things up- heat works (just in time for summer!). He also added a different seal to try and keep water out. We had quite the rain tonight so I’ll hopefully get a moment to check it out inside tomorrow.