Haven't had this happen before.....

[fredhargis]

Been fighting a problem I've never had before, and didn't even know it could happen. The gas line to the house froze up. This is LP, and the regulator to the house apparently froze. Yesterday I noticed when i was trying to start dinner (supper to most) that the gas range wasn't working. I checked everything, then went to the shop where the furnace was working fine...the shop is on the same tank as the house, but fed through a different line/regulator. Next step was to pour hot water on the house regulator and VIOLA, I was able to cook dinner. About an hour later the range didn't work again. Called the LP supplier this morning, they will be out to add methanol to the gas tank, my immediate fix was to wrap the regulator with a 6' heat tape and insulate it. So for the moment we have gas.....in a good way. The methanol is supposed to absorb the moisture that's (apparently) in the tank. I was thinking the regulator itself somehow picked up some moisture from the rain we had last Friday.

[R Clark]

Wow, thanks for posting that Fred.

My tank setup sounds exactly like yours.  The gas line from the tank does an immediate split; one to the house regulator, and one to the shop regulator.

I would never have expected a freeze up, either.  My propane supplier has never mentioned the possibility.  Good to know there's an easy-sounding fix.

I need to call them anyway and find out when our next delivery is.

[Snipe Hunter]

You are on the right track adding heat to the regulator. It doesn't take much heat. Water isn't necessarily the issue but the ethanol will help prevent it from freezing. Ambient heat is needed to convert the liquid propane to vapor. When the liquid converts to gas, it gets even colder. Humidity will frost up the regulator which can cause problems too.

[Stwood_]

Yes, one of the downfalls of LP

[fredhargis]

I've had the heat tape (6', 42 watt) on the regulator for 2 days now and things have worked fine.  I did wrap the heat tape/regulator with some pipe insulation and cover that with a plastic bag to keep it dry (remember, this is a temporary solution) but so far it's solved my problem.

[Snipe Hunter]

I've had the heat tape (6', 42 watt) on the regulator for 2 days now and things have worked fine.  I did wrap the heat tape/regulator with some pipe insulation and cover that with a plastic bag to keep it dry (remember, this is a temporary solution) but so far it's solved my problem.

Be careful. Kind of a rule of thumb: 

Don't insulate the regulator, it will prevent ambient heat from warming the regulator. Remember, the the expansion of the liquid to gas inside the regulator is basically how an air conditioner or refrigerator removes heat and cools the inside. You basically turned your regulator into a freezer by insulating it. I guess it's all good if you know the heat tape is turned on and heating. But if it isn't, you created a situation where it will freeze up in even warmer ambient temperatures.

[fredhargis]

Understand I'm not arguing or disagreeing with you, but I'm trying to understand. The regulator on the tank is on the top, so it only has gas going to it (?). That regulator knocks the tanks pressure down somewhat, then the gas goes to the house regulator (which is the problem) which simply knocks the pressure down some more. So isn't the evaporation all in the tank???

[Snipe Hunter]

Understand I'm not arguing or disagreeing with you, but I'm trying to understand. The regulator on the tank is on the top, so it only has gas going to it (?). That regulator knocks the tanks pressure down somewhat, then the gas goes to the house regulator (which is the problem) which simply knocks the pressure down some more. So isn't the evaporation all in the tank???

If I understand my learnin' correctly, it happens at the regulator but... I would ping BlackHat. He works with this stuff, I just read about this stuff.

[Snipe Hunter]

Understand I'm not arguing or disagreeing with you, but I'm trying to understand. The regulator on the tank is on the top, so it only has gas going to it (?). That regulator knocks the tanks pressure down somewhat, then the gas goes to the house regulator (which is the problem) which simply knocks the pressure down some more. So isn't the evaporation all in the tank???

Had to re-read some things. You are right. We're both right. The pressure reduction (gas expansion) of the vapor at the regulator reduces the temp inside the regulator causing the regulator to freeze up.

My comments about insulation and latent heat are still right. I was wrong about liquid propane turning to gas at the regulator. You still don't want to insulate an LP regulator unless it is being heated. If it isn't heated, you are building a freezer inside the insulation.

[Stwood_]

The LP change from liquid all happens inside the tank. Regulators have nothing to do with that.