Furnace troubles

[Johm]

Our furnace keeps going off and on. 2020 Montana fifth wheel.

We are in sub freezing weather. It lights comes on then goes out. Fan runs normal. Propane feed is good as water heater and stove top works.

 

[Johm]

We are in sub freezing weather. It lights comes on then goes out. Fan runs normal. Propane feed is good as water heater and stove top works.

 

[AbdRahim]

Yikes. I would call a mobile tech and get it fixed quickly, rather than freezing while trying to figure it out.

 

[Johm]

Thanks but there are none in this area. Trying to bribe the local RV dealer but they are reluctant to work on a camping world product. We had a list of defaults looked at by camping world before we moved over here and none of them were fixed, have had to fix them all ourselves. We would never go or recommend them to anyone. Now the furnace in 20 degrees and a foot of snow.

 

[Gronk]

IF you have access and are comfortable doing so try cleaning the igniter and burner. Was the furnace functioning prior to this problem?

 

[Johm]

IF you have access and are comfortable doing so try cleaning the igniter and burner. Was the furnace functioning prior to this problem?

Yes, it’s a Dometic. I’ve changed the sail switch. I’ve made sure the propane is good by lighting the stove top and water heater. It will come on, ignight for a few seconds then the burner will go out and the fan runs. It will oscillate like that until the room temperature is met.

 

[Kevin D Pem]

Most likely the pilot lite sensor. Consider a Buddy heater till you can get it fixed. A pilot lite sensor is an easy fix and could be a bad connection.

 

[Gronk]

The burner on an RV furnace has a spark ignition (no pilot flame). The burner lights with full flame and the spark rod is then used for flame rectification. In other words, when the burner first tries to light the rod throws a spark to the burner and lighting the propane, then after the gas valve opens the spark rod is used to sense flame by using the flame to conduct electricity. If the spark rod is dirty you may or may not see the anything wrong with it, but use a scrubber pad to clean it to a nice shine. When the burner does light is the flame nice and strong and mostly blue in color? If it has yellow in it the burner itself may be partially plugged (spiders are good for this) or I have seen an orifice get partially plugged. Use nothing stronger than a toothpick to poke the hole in it. Also, you can have a board fail on it and it will act like that. My water heater did pretty much the same thing. I purchased a Dinosaur Board through Amazon and fixed it. HERE is a site that has some good troubleshooting instructions.

 

[TJ&LadyDi]

Here's the link directly to Dinosaur replacement circuit boards.

Dinosaur Electronics Company Information

Excellent product; I have used them in previous RVs with furnace issues.

Great diagnosis and advice above from @Gronk.

TJ

 

[Gronk]

Guess either they froze to death or got buried by the snow or forgot about us..........

 

[Johm]

The burner on an RV furnace has a spark ignition (no pilot flame). The burner lights with full flame and the spark rod is then used for flame rectification. In other words, when the burner first tries to light the rod throws a spark to the burner and lighting the propane, then after the gas valve opens the spark rod is used to sense flame by using the flame to conduct electricity. If the spark rod is dirty you may or may not see the anything wrong with it, but use a scrubber pad to clean it to a nice shine. When the burner does light is the flame nice and strong and mostly blue in color? If it has yellow in it the burner itself may be partially plugged (spiders are good for this) or I have seen an orifice get partially plugged. Use nothing stronger than a toothpick to poke the hole in it. Also, you can have a board fail on it and it will act like that. My water heater did pretty much the same thing. I purchased a Dinosaur Board through Amazon and fixed it. HERE is a site that has some good troubleshooting instructions.

Thanks great advice. It was a low propane output from the regulator.

 

[Johm]

Now we’re working on the toilet that will not seal after flushing.

 

[Kevin D Pem]

Now we’re working on the toilet that will not seal after flushing.

Please start a new thread so people see the results.

 

[Gronk]

Thanks for letting us know what fixed your furnace. Now for the toilet, what type do you have? Something you can try is to pour a cup or so of straight vinegar into the toilet and sometimes that will remove the calcium build up. I have had to even pull the seal (being the cheap SOB I am) and gently scrape the crustiness off then put the seal back in. It took about five days before it completely sealed again, but it sealed! IF you do that turn your water off so it won't knock the seal out of your hand.....

 

[Johm]

I really appreciate all the good advice. Well we ended up having to change out the furnace after all. Local RV guy had one in the next day $$$, as the manufacturer wanted us to send it to them because they couldn’t figure out what was causing the problem.
Still working on the toilet. Tried the vinegar and cleaned the seal. Will wait until spring as it’s 10 degrees and can’t turn the water off without removing all the insulation I’ve built around it. It’s a second bathroom so we can do without.
Some other things that might help RV’ers. Our cable connection had a very high db test that was affecting our satellite internet. After finding the coax splitter behind a wall in the storage compartment we figured out it was defective. Again the manufacturer told us to send it to them before they would replace it (I guess they don’t believe us) I rerouted a coax cable through the slid out to the modem.
The leak under our kitchen sink was fixed by me cutting off the fittings and replacing them as they were cross threaded.
We’re still trying to figure out how to keep the oven on as we think the fan keeps blowing it out. Thank goodness for the convection microwave.
Thanks again for all the advice and we hope this helps others.