Atwoof furnace propane problem

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GPAY

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I recently spent the night in my 2015 Hawk with an outside temp of around minus 10 degrees. Furnace ran fine with thermostat set around 50 degrees for a few hours but then shut down. I checked the propane in the morning and there was plenty.I even switched to a new tank but the furnace would not light. I checked to see if there was propane at the stove and it would not light as well. So...apparently no propane getting to either. A few days later in 40 degree temps there was no problem. Can anyone shed some light on this?
Thanks
 
Your tank probably got too cold to put out enough pressure to light the appliances. You might try keeping one of the tanks inside to swap out with the one outside when it gets that cold.


Charlie

Sent from my iPad using Wander The West
 
Only a guess, but since your stove wouldn't fire either, perhaps another item might be the LPG pressure regulator attached to your tank? I wouldn't think 10 degrees would freeze either the tank or regulator, but perhaps the internals of the regulator were disabled by the cold in your case?

Maybe someone else has had a similar experience.

Poky


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I spent 15 winters in the bush in W. AK...the last 7 winters, we used 2 propane/tanks for our stove...they sat outside the front of the house and were "exposed" to up to 30 below weather at times during the winter... and yes, at those temps the propane flow got very slow... I built a 3 sided box with 1" styrofoam insulation(duct taped the seams believe it or not) and strung a trouble light w/ a 100 watt bulb...when temps went below 0, we turned the light on...with the insulation box and bulb heat, the propane flowed as needed to our stove through those extreme temps...

Not sure how this might translate to the 2 x 10 gal tanks in our campers... maybe a 40 w. light bulb in the storage box would do it especially in that small space... worth a try...shouldn't draw too much power or be a problem especially if you were plugged in at your camp spot..

Let us know what you come up with and what works...
 
I don't know much about the combustibility of propane fumes, but does it seem there would be a danger of ignition from a spark at the light switch in that enclosed propane cabinet?

Sent from my XT1254 using Wander The West mobile app
 
Couple of points in this interesting discussion:

Poky the OP said: -10 degrees not 10 degrees.

The propane tanks are 10 POUNDS each not 10 gallon...I believe 10lb tank holds 2.5 gallons of propane..

Looking forward to hearing a definition of the exact problem and a solution.

Also: "GPAY" @ -10 degrees F how did you handle the on-board water system? Plumbing and tanks.

Thanks,

Phil
 
I’m not an expert by any means, but I’ve spent many a cold night in my camper from 15 to 0 degrees. I’ve never had any problems with any part of the propane system (heater or stove). Last year we spent one night a -17 degrees. I utilized a Buddy heater while sleeping to save battery and noise, but at approximately 4:00 AM I got up and turn the heater thermostat up to 60 degrees and all worked well. Other than a whole lot of condensation (but that is another thread)

Anyway I’m not sure but propane (liquid) is something like -215 degrees and any temp above that you have vapor and pressure. I would check the propane lines and valves for possible water and/or dirt as the problem. Sorry you’re having a problem but I really don’t think it’s the tank. I could go on to barbecuing on the deck at the house with the same kind of propane bottle at below zero temps during this X-mas season with no problem so in my opinion it’s not the temp of the propane bottle.
 
Not to hijack this thread, but I had a problem this past weekend with my Atwood. It worked fine until day 2, then when I turned on the thermostat, I could not even get the blower to come on, no fan, no ticking indicating it was trying to lite.

Thoughts.
 
As noted in one of the above articles I have had a water/oily mix form in my propane lines. I was having some propane issues a couple of years ago and finally disconnected lines from the regulator and blew each one out from the appliance end. No more problem.
The Butane content of "propane" can vary quite a bit from North to South because down South they don't have to worry about extremely cold temps like we do up North. We filled one 20# tank in Florida a bunch of Easters ago and that tank would not run the furnace when we got back up North to 10 degree temps. The tank that was filled up here worked fine.
In the days before the new tank valves our local propane dealer would pour some Isoprophyl alcohol into the tank thru the valve to absorb any water prior to filling the tank. I wonder if some alcohol could be poured into the fill hose prior to connecting it to the tank for filling?
Happy New Year, Bigfoot Dave, Duluth, MN
 
Good points PAU....as the temp gradient of the propane and the ambient temp at the regulator becomes less the pressure of the propane gas becomes less. Propane is a liquid in the tank due to pressure in the tank; raise the temp of the propane above the "boiling" temp and pressure of the gas above the liquid increases. Higher temp gradient; higher propane pressure. Having said that it is hard to imagine a low enough 'outside' the bottle temp that was dramatically reduce the flow of gas to the point that it stopped all together. Or that moisture in the propane could freeze in the appliances.

For example dive gas is dried; I assume propane is also 'water free' [never a 100%] and I don't know if the propane valve has a 'snorkel' that extends into the propane tank like dive cylinder valves which could restrict low temp propane flow.

Wild card is the regulator and/or automatic flow restrictions at high propane flow [pressure differential] rates [FWC regulator has this] when regulator is first pressurized from propane tank. Once this auto feature is out of the link and allows full propane flow [smaller pressure differential] I don't know if an introduced abnormally high flow rate will again actuate the restricting valve, but I suspect it will; because the auto restricting valve is to limit propane flow if a line or valve breaks which would allow a high rate free-flow of propane into the camper.

SCUBA regulator first stages [reg valve on tank valve], even with 'dry air', can freeze OPEN at high flow rates [normally a free-flowing second stage] at low water temps with resulting low temp air then an additional drop in temperature via the Venturi Principle/Effect at the first stage [largest pressure drop/speed of gas].

Suppose an extreme ambient cold temp coupled with a high demand propane flow for the heater could activate the flow restricting device or if the regulator free-flowed and activate the restricting valve.

Pure guess work about the propane as my experience is with compressed gas and not liquid under pressure.

Phil
 
PAU in Montana said:
Anyway I’m not sure but propane (liquid) is something like -215 degrees and any temp above that you have vapor and pressureI could go on to barbecuing on the deck at the house with the same kind of propane bottle at below zero temps during this X-mas season with no problem so in my opinion it’s not the temp of the propane bottle.
Click to expand...
You are thinking of the freezing point of propane (-188ºF). The boiling point of propane is -45ºF. At 0º propane has a vapor pressure of 24 psi, 11 psi at -20º, 0 psi at -44ºF. Using a low pressure regulator interior gas pressure must be 0.4 psi above ambient (~ 14 psi, so about 14 1/2 psi). So somewhere below 0ºF propane will not flow; not enough internal pressure to open the regulator valve.

Below -10ºF I have a weak yellow flame in my grill after a few minutes of burning.

jim
 
murphy744 said:
Not to hijack this thread, but I had a problem this past weekend with my Atwood. It worked fine until day 2, then when I turned on the thermostat, I could not even get the blower to come on, no fan, no ticking indicating it was trying to lite.

Thoughts.
Click to expand...
From here, I found the following:
"Lock-out & Reset
Newer furnaces may go into “lock-out” if a potential safety problem is detected. Lock-out simply
means that the Control and/or ignition circuits shut down and do not allow furnace operation.
Lock-out can be reset by turning the thermostat switch off and changing the Set Temperature to a
low enough value so there is no demand for heat and waiting 10-15 seconds. Then turn the
thermostat on and set the temperature to the desired level and the furnace should attempt to start
again."

Might help. Good luck. A cold camping buddy is not a happy camping buddy.

Paul
 
JaSAn said:
You are thinking of the freezing point of propane (-188ºF). The boiling point of propane is -45ºF. At 0º propane has a vapor pressure of 24 psi, 11 psi at -20º, 0 psi at -44ºF. Using a low pressure regulator interior gas pressure must be 0.4 psi above ambient (~ 14 psi, so about 14 1/2 psi). So somewhere below 0ºF propane will not flow; not enough internal pressure to open the regulator valve.

Below -10ºF I have a weak yellow flame in my grill after a few minutes of burning.

jim
Click to expand...

Help me understand..."somewhere below 0 degrees F propane will not flow"...OK but how much below 0 degrees? I see 0 psi @ -45 and 11 psi @ -20 or about 4.1 psi too low to flow with a .4 psi differential you mentioned [assuming seal level 14.7 psi]..

Sounds reasonable but I guess the question is how much flow at what pressure does a FWC furnace, hot water heater or stove need to burn with a full flame [or partial flame on the stove] or another questions is at what point will the furnace and hot water heater fail to auto-light?

Wonder if FWC has the answers to the questions posed on this thread?

Phil

Ps...just read PaulT's reference and it states that ALL propane appliance are designed to operate at 3 psi...wow..that is damn near nothing..this does not speak to how much psi must be delivered to the regulator on the propane tank to realize the 3 psi at the appliance. It would appear that is about 18.1 psi into the regulator.

Honestly this stuff just doesn't square with actual use of propane appliances during below zero temps. Who here has fired up a propane stove at -15 or -20 degrees?

PPs....OK got it...check out this site http://countryplans.com/smf/index.php?topic=10186.0

With our small 10lb tanks we are severely limited in vapor pressure the tank can deliver at low temps...never thought of that. Size does matter...good article and discussion. Heck even hand warmers taped to the tank might help inside the storage box...otherwise you bring the tank inside the camper and the furnace will heat up the propane...not a solution really.
 
PaulT said:
From here, I found the following:
"Lock-out & ResetNewer furnaces may go into “lock-out” if a potential safety problem is detected. Lock-out simply
means that the Control and/or ignition circuits shut down and do not allow furnace operation.
Lock-out can be reset by turning the thermostat switch off and changing the Set Temperature to a
low enough value so there is no demand for heat and waiting 10-15 seconds. Then turn the
thermostat on and set the temperature to the desired level and the furnace should attempt to start
again."

Might help. Good luck. A cold camping buddy is not a happy camping buddy.

Paul
Click to expand...
Thanks Paul, I will check this out...cheers
 
Some really good stuff here and thank you all. I will re post if problem arises again. i think I'll put some Reflectix in the propane box if only because I have some extra.
Perhaps I should have noted that my Hawk is a shell with furnace, stove, seating and some other options but no water system so no issue there.
Thanks all!
 
murphy744 said:
It's a mechanical thermostat. I also checked all the fuses?
Click to expand...
Ah. Mechanical thermostat. You didn't happen to bump the thermostat's Off lever far enough over to disable the thermostat circuit did you? I once spent an embarrassingly-long time figuring that one out. The temp lever felt right and made its regular clunk so it didn't occur to me to look more closely at that sneaky Off lever.
 
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