I recently had issue with my Atwood furnace AFMD30. My problem started after towing home in a heavy rain. When I got home I washed the RV. After washing I entered the RV I noticed that my furnace fan was on low and appeared to be trying to lite. My Thermostat was off. The only way to turn off the furnace was to pull the 12 volt fuse in the power distribution center.
Looking online I discovered several potential problems but the one that made the most sense was water sitting getting under the furnace circuit board.
I removed the outer furnace cover which exposed the inner workings of the furnace including the circuit board. I removed the circuit board which had a teaspoon of water underneath. The problem is that in some Atwood furnaces the circuit board lies flat on a plastic shelf, water gets under the board and shorts out the board.
If your board looks like this you could have a future problem.
I dried out the area and dried out the board using compressed air.
It did not fix the problem right away so I emailed Atwood who is aware of the problem and has a fix for it. The fix is a new circuit board that flips the board and mounts it at a steep angle. They would provide me with a replacement free of charge but they would not ship it to me without going through a authorized dealer.
I contacted a authorized dealer in my area and told them what Atwood told me, and if they would contact Atwood for a FREE retrofit circuit board. They acted like they were snake bit...FREE! Well, that did not go well. I figured I would recontact Atwood. They reconfirmed that they would not mail it directly. Luckily for me my board had a day to dry out and it started to work normally. My board had not shorted completely out. So I decided to do my own retrofit.
I simply bought a couple of threaded 1/2" rubber inserts to slightly tilt the circuit board. This would get the board out of any future standing water and tilted, any water should run off and not settle.
Fix:
I'm not sure how the water got in maybe from the rain or when I was washing the outside and the water got in from above where the vented refrigerator vent is. My rig is only 3 years old and gaskets are in good shape.
If my circuit board had completely shorted out I would have found a dealer that would work with me on a retrofit Atwood board. If you have to buy the retro fit board it will be around $130.
Part number 95575
Interesting on the retro fit board. They flip the board upside down and at a steep angle. Flipped upside down soldered circuits are facing up! That just does not seem like a good idea to me but what do I know.
2017 Coleman 300tq by Dutchman Toy Hauler. 34.5 feet long and under 10k Gross. 500 watt Solar 2000 watt Inverter, 1999 Ford F250 2WD 7.3 4R100 DP Tuner, S&B Cold Air Intake, Gauges, 6.0 Trans Cooler, Air Bags.