New propane tank won't flow in freezing weather

[SailorDon]

I de-winterized my travel trailer a week ago thinking that here deep in the heart of Texas, I wasn't going to get any more freezing weather this winter season.
When I woke up this morning it was 29 degrees outside.
I went out to my travel trailer, turned on the propane tank valve, selected the tank with the switch over valve, and turned on the furnace. It blew cold air for about 30 seconds and shut down.
I tried the propane stove. No sound of gas coming from the burner.
Went outside and checked the switch over valve. It indicated red. That was strange since I've only used the propane for a couple of hours since I bought my travel trailer.
I closed the valve to that tank and switched over to the other propane tank which I had never used.
Everything worked fine, furnace, water heater, propane stove. (I didn't check the propane fridge.)
I dodged the bullet with the light freeze. No ice in the lines. All the plumbing worked fine, even the outdoor shower.

Later in the day, when the temperature was up to 45 degrees, I switched back to the original propane tank. It worked!
And of course the switch over valve indicator had changed from red to clear.

I read in the owner's manual that overfilled propane tanks can freeze up on high demand of propane. I wonder if the first tank I tried to use was overfilled?

What do you do if you get an overfilled propane tank freeze-up and you need to get the furnace going to prevent waterlines from freezing?
The owner's manual also says something about getting the propane dealer to add anhydrous methanol to the propane tank when refilling to prevent water or condensation freeze-up in cold weather. Does anybody do that?
This is all new to me since I have only done warm weather camping and used propane for hot water and cooking.
When winter comes, I drain and fill the water plumbing with RV anti-freeze for winter storage and never heat the travel trailer (until this morning's "emergency").
.

 

[danemayer]

Hi SailorDon,

The propane tanks have an overflow protection device that can trigger if you open the valve too fast. That's the most likely explanation for what you experienced. When this happens, close the valve, wait 10-15 seconds and reopen very slowly.

 

[NWILSON]

Dan is probably right! There is also overflow protection in the pigtail line between the tank and regulator. Any time you fail to get flow from a tank that you know is not empty, try shutting it off, disconnecting the line then reconnecting and VERY SLOWLY reopen the valve.
All tanks from 4 to 40 pounds now must have overfill protection devices (float valves) so there's not much chance of overfill being your problem.

 

[hoefler]

Another thing to consider; a new tank needs to be purged of air when fill for the first time. Otherwise you will get a big air bubble at the top of the tank ( propane is heavier than air ), that has to be purged first.

 

[SailorDon]

The propane tanks have an overflow protection device that can trigger if you open the valve too fast. That's the most likely explanation for what you experienced.

Dan,
Thank you for the info on slow opening of propane tank valves.
I can't prove it, but I'm sure that was the problem I had yesterday morning. I opened the valve on top of the propane tank too fast.
Not knowing about the overflow protection feature, I opened that valve as fast as I could. My motivation was it was 29 degrees out there and I didn't have my gloves on.

I could not reproduce the 29 degrees outside temperature to do the sub-freezing test. It was 44 degrees this morning when I did the "slow open" test.
Everything worked perfectly.
From an experimental point of view, I wish it had been 20 degrees, but I am satisfied yesterday's malfunction was due to operator error (opening the valve too fast).

I wonder why Heartland didn't put that important piece of information in their owner's manual.
Perhaps they assume we are all experts in the operation of propane systems.
.

 

[TedS]

There is a check valve in the pigtail hose connected to the tank. It is normally open. If you open the tank valve quickly and there is no pressure downstream the valve will check closed. It has a slow leak built in and when the pressure downstream equalizes the tank pressure, the check valves will open. If appliances are ON at that time, the pressure will not equalize and the valve remains closed. Turning OFF the appliances and waiting a minute or so will get the check valve to open. Or turn the tank valve OFF, wait then open it slowly will work, too. That check valve will close if there is a sudden break in the system plumbing to prevent sudden loss of propane.

 

[Lynn1130]

I have camped/hunted in temps down to 10 F and not had freeze up issues. 29 would not likely freeze the lines or tank.

 

[Jim.Allison]

The thing that will freeze up a tank is taking to much propane to quickly off the tank. This has to do with the area of the propane from which the fuel you are using is being vaporized. Running on 2 tanks provides more area from which to vaporize the LP and reduces the refrigeration effect per square inch of surface area. The upshot is that when using a lot of propane it is better to use it from two tanks at the same time. This only applies to generators and furnaces in the fivers.<object type="cosymantecnisbfw" cotype="cs" id="SILOBFWOBJECTID" style="width: 0px; height: 0px; display: block;"></object>