Furnace, Fridge & Propane Troubleshooting
The 1978 Chinook I got had come with all the propane and original appliances. It did not come with a tank, so my first step was finding a replacement horizontal tank. It was easy to find a new one at homedepot (delivered to store).
I also made sure to find a 11WC dual stage regulator from Camco to avoid issues with running all 3 appliances at once, also a dual stage is required for most modern RV’s. The tank was slightly larger than the original, so I had to cut some fiberglass and re-box the top of the tank area. It was about 10MM to short.
After getting the propane box re-glassed I was able to pull the stove, pull the fridge and pull the furnace. The only appliance I was able to get cleaned and working on a bench immediately was the stove. The fridge may have had too much rust/corrosion to function. I started looking at replacements and was able to find a Smead 3-way fridge with slightly smaller dimensions.
Smead sells them directly on their website, and I was able to confirm that it was tested and working on my bench after letting it settle a few hours after shipping. It’s not as wide as the original or as deep so it should be easy to re-install in the chinook. I got a 1in piece of foam insulation to offset the size and prevent an air gap. I haven’t installed it yet, but have it ready once I get the furnace figured out.
The furnace is a suburban NT-12 with a relay for controlling the fan & propane gas burner. Per the instructions, regardless of gas the fan should kick on when the thermostat is triggered. This was not the case, so I knew something was wrong electrically. Whoever had it before me had taken it apart partially and just left it unplugged. I started Looking at the manuals that came with my chinook and broke out my multimeter and discovered the problem.
I was able to determine that the coil of the relay was not functioning properly. It did not create magnetic force to pull the arm of the relay. Upon closer inspection there appears to be corrosion and some broken wires in the coil most likely from residual moisture.
There was an RV repair place on the east coast that used to carry drop in replacements but they had just sold their last replacement. I was able to determine that SPDT relay should be able to replace it easily. The Normally Closed pin is not used.
I got everything wired up on the bench at got it working! The Fan engages first, and then once the fan switch is engaged (by air) the solenoid for the propane gets engaged! it was a super rewarding experience to tear it down and understand how it works. Miss manuals that give the electrical diagram so you can actually troubleshoot without reverse engineering.
My next steps are to get the new fridge installed and replace the faucet/water system and fresh tank since it’s the original. Stay tuned for the fridge and water system install!