Question about frozen water line (Hope: rent, house, crawl space)

[cujo1950]

I've been down South since before the holidays and we're returning home next weekend. I've been watching the weather forecast and it looks like I'll be returning to frozen water lines. I have PEX lines and a couple run in the crawlspace under the house. I had a buddy go turn the heater on to 65, but in case, what do you guys suggest as the easiest way to thaw PEX? Do they rent some type of heater/blowers or am I going to have to spend time under there with a hairdryer?
Thanks for any help,
Steve

[Sage of Sagle]

Steve,

Are these in long runs along spans, or concentrated in a fairly small area? If they're in a small enough area, a propane heater could make sense to me since you have outside air already venting in that space so it would be safe, and you could channel the air to rise into the space around the pipes. If it's along a very long run, you could use cardboard to close in the bottom of the joist run and then blow in hot air down one end to create a really warm zone in there.

[javatom]

You should never let water lines freeze. If you have exposed water lines in a crawl space, it was installed wrong. Even if the lines are up inside the insulation it will be a problem if you have turned the heat off. Your choices are 1) leave the heat on. 2) winterize the house by draining all the water out of the lines. Even with pex, frozen lines can burst. It usually happens at the fittings or the hose bib. There should be someone monitoring the house with the heat now turned on. If there is a burst pipe it will cause a flood as it thaws. If no one is there to turn the water off it will end bad for you.

[cujo1950]

I did turn water off before leaving and heater is on but these lines are under the floor insulation and are pretty long runs.

[javatom]

You may want to have it re-installed just below the subfoor. You have a pipe installation that could freeze no matter what the temperature is inside the house. Can you get to the insulation, pull it down and push the pipe up. Then you can put the insulation back in and the heat of the house will keep the pipes from having problems.

[chevpu1967]

My girlfriend just bought me a thermostatically controlled outlet that comes on about 35 degrees and goes off about 45 degrees. A good thing to have for the well house with an electric heater or even a 150 watt incandescent light bulb. Just a thought. :-)

[Sage of Sagle]

Originally Posted by chevpu1967

My girlfriend just bought me a thermostatically controlled outlet that comes on about 35 degrees and goes off about 45 degrees. A good thing to have for the well house with an electric heater or even a 150 watt incandescent light bulb. Just a thought. :-)

Well, if he can access those lines, it would be good to wrap them with a heat coil on a thermostat switch, yeah...that would help in the future in a case like this...

[banjomike]

Heat tape does wonders for winter pipe problems, but the easiest thing is to crack one faucet open and let it run a thin stream when the weather is below zero.

But with Cujo's house warmed to 65º, I don't think he'll have a bad surprised waiting when he gets home. The crawl space is around 30º above freezing at that temp setting. Considering that only 1 or 2 degrees of warmth is needed to prevent a freeze-up, that's a wide safety margin.

[javatom]

I know you all mean well with the advice. But maybe it should be fixed properly. BTW heat tape can melt pex.

[cujo1950]

Hope you're right.
Here's what I've got