I need help tracing the source of a propane smell inside my 2016 FC 25 FB Twins that I detected during the course of dewinterising the unit to get ready for our first Spring trip.
I am on Vancouver Island seaside so we have moderate temps over the winter. Except for all of February (which was all below zero) it did not freeze much. I blew out the air lines, drained everything, shut down the systems, plugged the unit into house power and plugged in a thermostat controlled oil-filled heater inside plus a small fan to move the air around. The temp was set at +10C (50F). I left the Use/Store switch by the door at Use.The propane was off at the two 30lb tanks. I checked inside the unit weekly and the temp was maintained as set.
I began my dewinterising with the propane system. I opened one propane tank. I started with the stovetop burners. I have only the stovetop as we opted for the Couture convection microwave instead of the propane oven.
The stovetop has three burners one front and two rear. I use a propane BBQ starter gizmo to ensure I have an ignition source when I open a burner valve, with the plan being to test the spark igniters later after all ignite property.
I started with the front burner. After opening the valve it took a few seconds for the propane to reach the stove from the tanks and then the front burner ignited. However, it was not the blue flame expected but instead it was a completely orange flame about two times larger than the blue flame ought to have been when lighting. I shut it down.
I knew from my propane stove in the house that when the diffuser a a burner is not properly seated or has junk in it that it gives off an orange flame so I was not then worried. I checked the two rear burners and they came on just fine.
I then took the front burner diffuser off (quarter turn then pull up). It looked like it was already seated but I thought it couldn’t hurt to take it off and put it back. I reinstalled it making sure it was seated well. I then tested the front burner again using the BBQ lighter.
This time there was a short delay before the propane ignited but the flame I got was more than anticipated. The burner ignited but I also got a stove wide puff of orange flame shooting out at me at crotch level. (Yes I know every male reader just cringed). I turned off the burner control and the flame died out right away. I’m not sure because it happened so fast but I had the sense that the “crotch flame” came out the air vents in the fascia that surround the convection microwave. It may have come out where the stove top meets the counter but that’s not what I sensed at the time.
After checking to make sure all was intact and after letting the stove top fittings cool I again took the front burner diffuser off. I thought that maybe there was a critter in the now exposed gas pipe so I put my lips on it and gently added air pressure and met resistance. Maybe there was supposed to be resistance at the valve - I don’t know. Anyway, I gave a light “puff” with my lips and felt the resistance clear. I reassembled the diffuser.
Standing slightly farther back I tried to ignite the front burner again and it lit and burned perfectly. I did not smell the “rotten egg smell” from the propane at anytime through all the above (in Canada propane is required by law to have an added odourant (I don’t know the situation in the USA).
Great, I thought and proceeded to test the fridge, furnace and HW heater on propane and all worked flawlessly without any residual propane smell.
I tested the heat pump and after it worked fine I quit intending to get the water systems going in a couple of days. I left the propane tank on. One roof vent was left open.
When I sent out to do the water sytems a few days later I smelled propane as soon as I entered the inside of the unit (no smell outside). It was not a heavy smell but it was present. I’m very sensitive to sulphur odor. I opened the door and blew the place out quickly with the Fantastic Fan and the range hood fan (not thinking at the time about possible electric sparks … duh). I turned the propane off at the tank.
After the smell cleared I tried igniting the front stove burner with the BBQ starter wand and there was residual pressure in the line and the burner ignited but burned out in a few seconds. I then tried to light the other two burners but no further propane was present in the lines.
I then closed up the unit leaving the roof vent open.
After an hour I went back out and upon entering I smell the same low level propane smell even though the tank valves were shut. I aired the unit out again, I unplugged the shore power, turned off the fridge and flipped the Use/Store switch to Store shutting down the 12v
system. I closed it up leaving the roof vent open.
I let an hour pass and upon reentering I could detect the faint propane smell again.
Any ideas why I’m getting the propane smell in the unit?