Water In The Furance

[Ceratto's Grotto]

Our Atwood furnace was not igniting tonight. I could hear the attempts but it would shut down after a few failed attempts. I checked the propane levels via both the inside and outside gauges and had almost 1/2 a tank. I switched over to the heat pump (A/C) and it worked fine so I figured the thermostat was probably not the problem. Opened up the inspection panels to the furnace and found a small amount of water in the bottom of it where the fan cage is. I noticed that the circuit board was mounted very low and although water was almost touching it, it wasn't... until I turned the fan on and the vibration actually moved the water up onto the bottom of the circuit board (fluid dynamics I suppose). This caused the board to sense a fault and it shut down (the blinking circuit board LED indicating a start fault). I looked for water leaks into and onto the furnace area from water lines, fridge ice maker lines, fridge evaporation devices, etc., and found no leaking water sources. I cleaned up and dried the area and it works fine (although I have not ran it more than a few minutes long to see if more water appears, (I'll check again tomorrow morning). My thought right now is that the water was created by the furnace itself via condensation and or water in the propane supply itself. Does anyone have any thoughts or experience with this issue?

[RV Wizard]

While I have found over the years ; anything is possible, you are talking about a lot of water to be coming from the propane as the source. I would think that other appliances would have a problem with it as well. I see you are in Az. and so you probably have not seen much rain. I wonder if you could have a drain from a washer or shower that is leaking? Or could you have washed the coach recently? Good luck in finding the culprit and do keep us posted. Thanks

[Hillbilly2]

I don't know if RV furnaces are the same, but with the high efficency gas furnaces in homes, they have a condensate drain that when plugged or stopped up the water will back up into the combustion fan, causing a start fault condition. (the water slows down the fan to a point where the PD switch locks out the gas valve, I won't go into the technical detail, as everyone would get bored) Does it sound like sloshing water when the combustion fan starts? if so that is the problem. Check for a drain hose from the furnace.

["007"]

Check along the top edge of your furnace and make sure the edge has sealent to stop water from rain or washing side walls of coach is not allowed to flow thru.

[Gary RVRoamer]

There is no condensate drain in an Atwood RV furnace, at least not in any model I have seen. My guess would be that water ran in from above or blew in (wind or hose pressure).

Theer are gaskets on the back side of the outer door panel that are supposed to keep the air intake/exhaust side separate from the rest of the compartment. Maybe yours have deteriorated. That can be a CO poisoning risk as well as an operational problem.

[Ceratto's Grotto]

The furnace ran all night without a problem, but when I inspected it this morning there was, once again, a little water in the area, (albeit not enough to get on the circuit board and trip it). After more looking around for leaks, I found that there was a pin hole leak in the ice maker water line and as it was run just above the furnace, laying directly on the sheet metal housing, it dripped directly into the furnace fan box area through some vent openings. I inspected the ice maker water line hose suspecting that maybe it was a hole created by vibration since it was laying directly on the sheet metal housing of the furnace. There did not appear to be any wear issues, so I assume the pin hole developed via other reasons. I replaced the ice maker water line, trying to re-route it slightly to minimize 1) potential wear points due to vibration and 2) so if it [when it] leaks again it would not drip directly onto the furnace electronics area. It wasn't able to re-route it very well due to the original installation. I also tried to mount the furnace electronic circuit board a bit higher but that was not possible either.

Another area where a little better design, with repair and both systems coexistence within such close proximity in mind, could improve safety and maintenance.

Thanks everyone for your help!

["007"]

Thanks for the follow up Wally you never know what lurks behind these walls.