Furnace issue.
I am the owner of a 264bh. We went for our first cool weather trip this past weekend and had a problem with our furnace not firing the second night there. Temps got down to 28 degrees. I had one tank ...
Forum Discussion
pianotuna wrote:
itguy,
If the ambient temperatures were below the -35 range, vaporization starts to become an issue. At 28 F, he either has a faulty regulator, or more likely a Butane Propane mix in the tanks.
Vaporization can be an issue at much warmer temperatures on a low tank. Read the link I provided. It's for generators but still applies to an RV.
At 30 Deg F on a 1/4 full 20b propane tank you can only get 15.700 BTU/hr out of it. If your furnace is more than that (ours is 30k) you can run into vaporization issues.
Why this works is simple physics. As you vaporize the propane in the tank it will cool itself. Normally it's not an issue as the remaining propane liquid and surrounding air is warm enough to absorb that heat. But when it gets cold and you have low levels it can't and it will reduce the available BTU's. Propane will still vaporize but not at the rate needed to support the full output of the appliance. You can see a frost ring approximately at the level of the propane in the tank when that happens. And the output of the appliance will drop off substantially. Happens to us that grill in the winter. The flame gets lower and lower the longer you leave the grill on and the lower the bottle gets.
Those with in-ground tanks have less of an issue as those are large and they tend to be below the frost line so they are a constantly at a nice warm temp and use the earth as a huge heat sink.
The answer is always the same - larger tanks, more propane in them or warm them up. Warming them can be dangerous but many use warm or cool water.
Google around - happens all the time with the small bottles and high BTU loads. Google Propane tank frost to see what I'm talking about.
