Unfortunately the furnace still intermittent so decided to rip it apart. Because I put in a quick disconnect with about 6' of spare wire I could pull the furnace out of the rig and rest it on the tailgate of the truck, which made a great work bench.

After some internet surfing I found an on line service manual that is intended for training and a reference source for service technicians vs. A user manual that just tells you how to operate it. It included a trouble shooting flowchart which allowed you to test separate components to rule out the various piece parts and hopefully prevent the "order the parts and hope it fixes the problem" resolution method. The printed circuit board could be faulty but they're expensive so ordering a new 1 is a last resort.

First stop was to check the pressure right at the furnace propane hook up so I had to plumb together some fittings to hook up the manometer I made. The pressure was right on spec so that pretty much rules out oil contamination in the lines. Next I checked the various safety switches with a multimeter to test for proper functioning. All looked good so the only thing left to do was to rip it apart and get to the burner and ignition. That took about 45 minutes as there are some very fragile fireproof gaskets that I had to be very careful not to tear. Carbon monoxide leaking in the rig is a great way to spoil your day...and life. We have 3 detectors aboard so we should be covered if there ever is a leak.

Finally got to the burner nozzle and found bits of rust partially blocking the orifice. So, a quick disassembly and blow out and problem solved.....I HOPE! Reassembled everything and tested 4 times and it fired up and ran each time. The test will be what happens the next day so fingers crossed.

Got a few things at Dollar General including a case of 15 Keystone beers for $7. I know, I too was thinking what kind of barrel wash could this be but, it's made by Coors and it is actually really good! Need to put in some extra miles if I'm gonna be drinking this stuff!