Help needed with travel trailer heater

[GT2]

Anyone have any experience with propane heaters in RV's?
Before the season in Seattle it was working fine. I then moved it to my property in Idaho and the heater worked fine the first few times, but then started to get harder to fire off. Now it dosent fire at all.
The blower comes on and I hear the igniter sparking but no fire.

My other propane items work ( frig and water heater) but on initial start up they are slow to ignite, it takes 3 or 4 cycles to get going.
Is it possible the propane regulator is set too low?
Thanks, Tim

 

[Bird]

Too many possibilities. Yes, it's possible the LPG regulator is set too low, but I'd expect that to only be an unlikely possibility. Have you gone into the heater to look for mud dauber nests? How old is the unit? Does it have an electronic circuit board? Have you checked to see if the sail switch is working? Is the igniter still in the proper place? And even though both of my brothers have been in the business of RV service (one still is), my own experience with working on furnaces is very limited, and dated.

 

[GT2]

Too many possibilities. Yes, it's possible the LPG regulator is set too low, but I'd expect that to only be an unlikely possibility. Have you gone into the heater to look for mud dauber nests? How old is the unit? Does it have an electronic circuit board? Have you checked to see if the sail switch is working? Is the igniter still in the proper place? And even though both of my brothers have been in the business of RV service (one still is), my own experience with working on furnaces is very limited, and dated.

I have not opened the unit yet, have to remove some cabinetry to get to it.
Its 2004.
Sail switch?
Thanks, Tim

 

[Dutch445]

In the line from the tank(s) to the appliances,
where does the heater come in? I think in mine,
it's after the stove, but before the little water
heater in the back of the trailer. I find if I start
with the stove, get that lit, and let it burn a bit,
then move on down the line to get all the air out, things
finally do come on and stay on.
sometimes the water heater takes several (8 or 9) attempts
to get the air out of the line.

 

[Bird]

Tim, I think there are only two or threee major brands of RV furnace, and I know my brothers have replaced circuit boards in a number of them. Nothing more than a wild guess on my part, but that's what I'd suspect first on that late a model. And unlike my brothers, I wouldn't even know how to test one to see if it's defective.

The newer furnaces may not even have a sail switch, but the ones I owned did. Of course, my 6 personal rigs over the years were 1970 to 1992 models. With those older furnaces, when the blower came on, it blew a "sail" (vertical piece of sheet metal) that was attached by a rod to a valve. The sail turning was what opened the valve and let propane through.

Go to google.com and enter "RV furnace troubleshooting" and I think you'll find lots of help. The first entry I came up with showed both a circuit board and a sail switch, although the sail switch works an electrical switch instead of a propane switch; at least on that model.

Well . . . ., I said my experience was dated.

 

[Scooby074]

i doubt its your regulator, but it could be. your sure the tank is full? id check for your lines for obstructions. Ive had propene tanks, for whatever reason stop delivering full pressure, even when full. I think its something in the tank valve, because when i change over to another tank everything works. The new tanks have safety valves in them and i guess that may be the source of the problems. Usually when i have one of those tanks i mark it and when its empty it goes for exchange instead of refill.

Id try a tank that you know is working good (like on a BBQ) and go from there,

 

[Bird]

That newer safety valve you're talking about can sometimes restrict the flow if you just open the valve too fast. The solution is to close it; i.e., turn the valve clockwise all the way, then open it (counterclockwise) very slowly.

 

[Scooby074]

Thanks Bird, I usually follow that procedure, however once the tank stops delivering full pressure i cant get it back, even using that trick. I think its physically something in the valves that lets go? Before i started trading them in, ive refilled a couple thinking that it was do to low volume in the tank, but no difference. The defective ones still operate, but just dont deliver the gas. YOu can really notice it on the BBQ, because theres quite a difference in heat. Even the ignition of the 2nd and 3rd burners is much slower with the defective tank.

 

[Bird]

Sounds like you may have gotten some with bad valves then, Jason, and I'd swap them out, too, in that case. I haven't swapped any for awhile now myself because it's closer for me to just go to the Destiny RV Resort and get mine refilled.

Before i started trading them in, ive refilled a couple thinking that it was do to low volume in the tank, but no difference.

You likely already know this, so if so, you can ignore what I'm about to say, but if I have any doubt about how much one of my bottles has in it, I weigh it on the bathroom scales. Each bottle has a "TW" and a number stamped near the top. TW = Tare Weight = Empty Weight. So whatever it weighs above that TW weight is the pounds of LPG still in the bottle. You can figure about 4 pounds per gallon; actually more like 4.2 pounds per gallon, I guess.

 

[Scooby074]

I knew the tank wasnt full, but i imagine it was around 50%. Ive only had this happen with 2 tanks, and both the tanks were exchange tanks.

Personally i dont like the exchange tanks. Most are old and they rust out way faster than normal do to the lousy paint that the reman places put on them. Id rather just own my own and refill them. Then you know what you have. I think alot of problem tanks end up being exchanged when they give their owners a headache or are past their certification date.

The only reason i ended up with these exchange tanks was i was away from home and needed propane for my campers heater and the only refill place was 40mi away. Most of the country stores took out their refill stations (due to regulation and requiring a trained and certified refiller ) when these exchange stations took off a few years ago. But refill is still alot cheaper than exchange.

 

[GT2]

Go to google.com and enter "RV furnace troubleshooting" and I think you'll find lots of help. The first entry I came up with showed both a circuit board and a sail switch, although the sail switch works an electrical switch instead of a propane switch; at least on that model.

Well . . . ., I said my experience was dated.

Thanks for the tip Bird, a lot of good info there.
Looks like I should be able to diagnose with a volt meter.
The trouble shooting guide makes it sound like I have a faulty signal or voltage to the gas valve.
Tim

 

[GT2]

Thanks Bird, I usually follow that procedure, however once the tank stops delivering full pressure i cant get it back, even using that trick. I think its physically something in the valves that lets go? Before i started trading them in, ive refilled a couple thinking that it was do to low volume in the tank, but no difference. The defective ones still operate, but just dont deliver the gas. YOu can really notice it on the BBQ, because theres quite a difference in heat. Even the ignition of the 2nd and 3rd burners is much slower with the defective tank.

I too have followed that procedure, but have presumed that it was not the problem because the fridge, stove and water heater work semi normally.
Tim

 

[Scooby074]

I too have followed that procedure, but have presumed that it was not the problem because the fridge, stove and water heater work semi normally.
Tim

Do you have a second propane tank to try? WHen i was having problems with tanks, everything would work, just not well. A known good tank would confirm where the problem lies.

 

[johnk]

I say plugged pilot orfice. Probably a web in there...

 

[johnk]

I say plugged pilot orfice. Probably a web in there... Or.........Plugged vent on the main tanks regulator. Take the cap off the regulator and try the equipment. There should be a pin hile vent in the cap..

 

[2manyrocks]

I agree with JohnK. Would clean the orfice first. When you're in there, be sure to check that your exhaust vent is open and that mice haven't stopped it up. Don't want to get monoxide poisoned when you fire it up.

 

[mikefromnh]

When I had a problems with a lp tank I brought it back to the RV dealer, and they did the following:

1 - turn off valve
2 - disconnect tank
3 - lift tank about 3'
4- drop straight down on hard surface (several times)

Sometimes the new style valves need a little persuasion to work right.

I doubt there is a problem with your furnace if the other systems aren't working quite right.

 

[CurlyDave]

if I have any doubt about how much one of my bottles has in it, I weigh it on the bathroom scales. Each bottle has a "TW" and a number stamped near the top. TW = Tare Weight = Empty Weight. So whatever it weighs above that TW weight is the pounds of LPG still in the bottle. You can figure about 4 pounds per gallon; actually more like 4.2 pounds per gallon, I guess.

I have a 50 lb fish scale you hold in one hand with a dial and a hook on the bottom of it I use for weighing propane tanks. I think it was about $5, less than $10 for sure.

The advantage is that I don't have to bring the tank to the scale and I can weight it on any surface, even on a severe slope covered in leaves.