Furnace runs till out of propane
- Thread starter winona
- Start date
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If you have answers, please help by responding to the unanswered posts.
Tulecreeper
Well-known member
If that is true, then there are a couple of things that went wrong at the same time. Bad/leaking valve at the tank allowing propane to bypass, broken thermostat that reads off but is actually internally still set at a higher temp, etc.
Domo
Well-known member
Could you kindly post pictures of the heater and thermostat and the propane valve(s)?
You're looking at your furnace, not the water heater?
To verify, the furnace continues to blow heated air into your RV and never turns off until the propane is empty despite how hot it gets in your RV?
Do you have two propane tanks with any automatic crossover valve? (Thinking you may have turned off one tank, but the system switched to the second one until it runs out of gas, also.)
You're looking at your furnace, not the water heater?
To verify, the furnace continues to blow heated air into your RV and never turns off until the propane is empty despite how hot it gets in your RV?
Do you have two propane tanks with any automatic crossover valve? (Thinking you may have turned off one tank, but the system switched to the second one until it runs out of gas, also.)
Kirk
Well-known member
Both Atwood & Suburban use blue wires to the thermostat and when they are connected together the furnace will run until it loses a source of propane. Are you telling us that yours continues to run even after you turn off all propane at the tank? I suspect that you are telling us that the blower runs even without any propane? Or are you telling us that it blows hot air with the propane valve on the bottle closed?
It the blue wires are shorted together that will cause the furnace to start the blower and attempt to light the propane. More recent models will turn the blower off after a time if the controls do not sense heat from the burning propane but most of them just keep the blower running until it is turned off. Since you say that it runs when the thermostat is turned off, the fist thing I'd check is to make sure that the 2 blue wires are not shorted together. If the blue wires are not shorted, I would then look at the fan relay. We are just guessing to some extent since you have not shared the model of furnace so we can't check a service manual.
It the blue wires are shorted together that will cause the furnace to start the blower and attempt to light the propane. More recent models will turn the blower off after a time if the controls do not sense heat from the burning propane but most of them just keep the blower running until it is turned off. Since you say that it runs when the thermostat is turned off, the fist thing I'd check is to make sure that the 2 blue wires are not shorted together. If the blue wires are not shorted, I would then look at the fan relay. We are just guessing to some extent since you have not shared the model of furnace so we can't check a service manual.
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To clarify: yes, the propane is off at the permanently affixed tank and there is no cross-over since there’s only one tank. And yes, it’s the furnace that continues to run, and blows warm air since the “off” at the thermostat is nearest the lowest setting.
I’m suspecting a leaky valve somewhere and will schedule a repair. Checking wires in themostat. Thanks for where to start.
I’m suspecting a leaky valve somewhere and will schedule a repair. Checking wires in themostat. Thanks for where to start.
LarsMac
Well-known member
So, is this RV new to you?
OR, did this just start recently?
Did you recently have some work done that may have precipitated the situation?
Or, has it been going on for a while?
Any repair tech will likely be asking those questions, too.
OR, did this just start recently?
Did you recently have some work done that may have precipitated the situation?
Or, has it been going on for a while?
Any repair tech will likely be asking those questions, too.
Gary RV_Wizard
Site Team
Sounds like TWO problems to me:
- Faulty propane shut-off valve (leaks propane even when "off")
- Faulty thermostat (it's "on" regardless of temperature)
Kirk
Well-known member
Have you tried to light the stove top burner with the valve shut? If you can and you are sure that valve is closed, that would mean that the valve is bad and needs to be replaced. To do that you will need the propane tank to be empty.
RV is not new to me. Owned it since new in 2015.
Started last fall after I had run the furnace then winterized and parked in driveway. Yes, I ignored it in true fashion because “it’ll go away” and yes, the propane did, and the ole “I’ll tackle this later” which is now now. : -(
I had a propane leak the previous winter fixed at the dealership — which it wasn’t - then refixed (maybe?) as the dealer / repair put on wrong valve. Should I start a separate thread on poor repair work?
To be looked at this weekend.
Meanwhile, local dealer sold out to Lazydays which moved 2 hours east of me. A hassle, especially since I don’t tow.
In my grandmother’s famous words: if it’s not ants, it’s grasshoppers.
Kirk
Well-known member
As I asked before, have you tried to light the stove top with the supply valve closed? You might also be wise to see if there is a mobile RV tech in your area.
The propane tank is empty, so no, I haven’t tried to light the stove nor the hot water heater. Tried a mobile rv tech and he’s swamped.
Lou Schneider
Site Team
- Joined
- Mar 14, 2005
- Posts
- 13,344
The furnace will run until the interior temperature satisfiers the thermostat. Without propane to generate heat the furnace will run until you turn it off or the interior warms up to the thermostat's temperature.
Tulecreeper
Well-known member
Gee, that sounds familiar.
Kirk
Well-known member
Gary RV_Wizard
Site Team
Great minds running in the same channel.Gee, that sounds familiar.
Think of it as a vote for the most likely cause. When there are multiple and often differing responses, it helps the OP to learn there is a consensus.
If your propane tank is empty then now's the time to replace it with a new tank. Would likely rule out a faulty shut off. Then it's on to option #2 which is the thermostat wiring ,referring to Kirks post about the blue wires shorting out. Then replace thermostat if needed. Next is to sell the RV as its obviously occupied by the paranormal, ghosts are known to like it warm.
NY_Dutch
Well-known member
The service valve is replaceable for a lot less expense than replacing the whole tank.
Domo
Well-known member
Yeah, I think we all step on each other's toes pretty often. The good news is we get validation and the better news is that the "next poster" may correct any errors... (which I make often enough for me to make this comment!).Gee, that sounds familiar.
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OldWEB
Well-known member
Best is to keep it to yerself... someone else might benefit from your fix.
