Frozen Pool Pipes

by Gina

I have a 3 yr old in ground salt water pool that we keep open year round and run the pump 24/7. This winter the temps are getting down to zero and over night my pump shut off and I had about a half inch layer of ice on top.

My question is, how cold and for how long does it need to stay cold for the underground pipes to completely freeze and do damage?

It's supposed to warm up above freezing tomorrow. The pump started again but keeps shutting off. Is it better to keep trying to turn it on or just leave it off until it warms up enough?

Thanks for the question Gina

The water lines above ground generally the first to freeze. Ideally you want to drain all lines.

Some factors that will contribute to pool pipes freezing are:

- the rate of flow of the water through the pipes

- pipe diameter

- whether the pipe is in or aboveground as was stated before

- temperature

I've found that it may take over 8 hours for water to freeze solid in a 2" pipe without the pump running and with the temperature not getting above 20 - 25 degrees. If possible, try to drain it during the freeze period rather than rely on running the pump.

It's the freezing, then expansion, that causes the lines to break. However, it's virtually impossible for moving water to freeze solid.

My advice would be to try to keep the pump running as long as possible, but keep an eye on the pump pot. If it begins to strain you know there's a clog or frozen pipe in the returns. Turn off the system. Running a dry pump will cause it to overheat.

This is a "close the barn door after the horses get out" situation that many people are in right now.


Comments for Frozen Pool Pipes

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Jan 10, 2014
Pool Line Freeze
by: Gina

Thank you so much for the information. Yes this winter is definitely a rare event for Oklahoma. The guy that put in my pool said he’s never closed any of his pools so I’ve left mine open too…pretty sure I won’t next year! So I have one more question…the pump is going off every 15 minutes…is this a safety mechanism if it’s running dry?

I couldn't find anything in the manual that stated that but it was like clockwork. I know I’ve probably damaged my pump but it was flowing enough air/water to keep the top of the pool from freezing solid.

I figured replacing the pump might be cheaper than any busted lines or popping and cracking tiles. I guess I’ll find out this afternoon exactly how much damage everything caused.

It’s supposed to get to 40 degrees today after a 2 day bitter cold snap. Thanks again…you are a valuable resource!!

It does sound like the motor is overheating. You may need to replace it but without actually seeing it it's difficult to say. Remember that everything is either circulation or congestion.

Pump motors do have regulators that cut off if the motor gets too hot. This is to lessen the events of fire. If it's an electrical issue you'd be better off seeking a qualified electrician. Electricity and me are not on the best of terms. I can and have installed many motors and pump systems but I just don't have the mental capacity to fully troubleshoot electrical issues.

Variable and 2-speed pump run about $350. You may be able to get a re-manufactured motor for less or possibly do some work yourself. Many times the diffuser gasket, impeller, housing gasket, seal assembly, seal plate, and/or motor mounting plate are the parts that melt. You can either look in the owner's manual or go online and look at a motor diagram. These parts are pretty inexpensive and can easily be installed.

Hope this helps and good luck.


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