Propane furnace issue

[rmauk]

Our propane furnace shuts off with propane still in the tank. When the temperature is just below freezing, upper 20s, our furnace shuts off with 12lbs still in the 20# tank. Our gauge on the tank reads just between green and yellow. This is in a Viking 16RBD hybrid camper.

[whiteeye42]

i have used propane way below 0 and had no problems you might have butane in the tank which won't work much below 32 degrees i would have the tank drained of all gas and purged with propane and then filled with propane and make sure they are filling it with propane and not butane

[canoe_on_top]

Hope it helps.

[rmauk]

Canoe on top--Thanks.

[canoe_on_top]

Your furnace should work fine even at below zero temps. Lower temps do lower vapor pressure but, it has to be real cold for propane appliances to not work. Propane will not vaporize at minus 40 F. It's my understanding that at 40 below, you can carry propane around in a bucket. Low temperature is not your problem unless it is freezing your regulator. I had moisture in a regulator on a class C. It was confusing because when the temp got below freezing, the stove would work but the furnace would not. There was enough flow for the stove but not the furnace. The furnace would work fine in the dealer's shop but, not in the mountains when it got below freezing. Finally took it to an independent RV repair place. They diagnosed it immediately. Had to empty the tank of propane then, they added alcohol and blew it out with air. They replaced the regulator and everything worked fine after that.

[time2roll]

Could have some butane in the cylinder. If you have a heating pad put it on the cylinder to burn it off. Otherwise exchange the cylinder.

[midnightsadie]

might be you moving the black knob,,

[rmauk]

My tank weighed 28+ lbs. I weighed an empty tank at 17- lbs and deducted I had 12# propane remaining. I understand propane is problematic at low temps, I am just surprised that I am having problems just below freezing.

[eHoefler]

2 things

The tare ( empty ) weight of a 20# propane tank is 17#, if you tank weighs 12#, its empty and you scale is way off.

2nd, at that outside temperature, your propane may not be able to vaporize to meet demand of the furnace. Try warming the tank with a heating pad. They make a propane tank heat that attaches to the bottle.

[enblethen]

Here is main page. You have to go to "installation" to get to my previous attempt.
Fairview regulators

[deltabravo]

enblethen wrote:

Fairview two stage regulator

Hyperlinking to a file on your C drive does not work.

Your link goes here:

C:/Users/enble_000/Downloads/YY-INSTRUCT-GR-9950P%20%20GR-9959P%20and%20GR-9954P%20X-SERIES%20FAIRVIEW%20LTD-2019.pdf

[rmauk]

Oh.

[enblethen]

You should not be turning the black knob without using a manometer to properly adjust it.
Fairview two stage regulator

[rmauk]

The furnace is a Suburban and the regulator is a Fairview two stage. There is a black dial on the regulator. It screws in and out.

[BurbMan]

Again what makes you think that the furnace shutdown is gas related? It could be a moisture problem but there are other possible causes also.