Frozen Inground Swimming Pool Lines

I was out of town around the time that I should have closed our inground pool, we got lots of rain and everytime I tried to drain pool below skimmer it would rain again. Now I have water level up again, and the weather is about 13-28 degrees roughly in the evening and morning hours.

My pool lines have water in them and the water is most likely frozen. AM I SCREWED? Is there a temperature at which point I may be able to run warm water and try to thaw lines?

Could the water level be dropped somehow if I broken through a thin layer of frozen water that has formed on the surface? Should I not plug the lines (which I haven't done from the skimmer side or outlet to pool?


Thanks for the question

In the years that I took care of pools in Arizona, I only had 2 that actually froze up completely. We had a long cold spell that was very rare for Phoenix/Mesa, AZ.

First, you can get a submersible pump to drain the water out. Most pool supply stores should carry it. It's what I used when I had to drain and refill the pools I did.

It normally takes a week or two for the water in the filter, pump motor, and pipes to completely freeze up so that no water can get in or out. This is because many people don't allow their pump to run 6 - 8 hours per day, even in the Winter. Moving water can't freeze up, maybe if it's sub-zero for days on end, but in the teens and twenties shouldn't be a problem.

The important thing to do is to try to get the water line below the skimmer as quickly as you can, then get a shop-vac and blow the lines out as best you can. The hose to the shop-vac normally fits the skimmer inlet so that shouldn't be a problem.

Water in the pool lines doesn't mean that the lines will break, (because of expansion) but there is a greater probability that they will.

If you start the pump motor
and it primes and keeps the prime, chances are you still have good water flow throughout the system. Just because there is a thin layer of ice on the top of the pool doesn't mean that the lines are frozen.

My experience says that pouring anti-freeze in the lines will not thaw the lines out, it's only for preventative measures during a pool closing.

Calcium Chloride is a good de-icer and can be purchased at most pool supply stores.

If you can blow out the lines you'll want to plug them up so no water can get in and there are non toxic pool anti-freeze agents as well.

I'm not aware of anything a pool owner can do when the lines are already frozen on an inground pool being 99% of the lines are underground.

Even if you can get some of the water out of the lines using a shop-vac will help. Less water means you lessen the chance of expansion and cracking of the pipes. If the pipes are frozen solid, the temperature will have to be above freezing, at least 35 degrees for a couple days before any good thawing can occur.

If you have a pool heater, contact the manufacturer of the heater and ask them what's the lowest water temperature you can safely run the heater. If they say pretty low then you probably can run it 24/7. This might heat up the pool enough so you can close it. You might want to get a solar blanket/cover while this is going on to keep as much heat in the pool as possible.

Hope this helps and good luck with the pool


Dec 21, 2010

Thanks for the info... NEW
by: JKN

I was able to get to the skimmer box and chip the top layer and behold ....there was the water!
I shop vac'd as much as possible and blew the lines as much as possible however it still appears like there is water in the lines.

Now my worries are the inlet to the pool!
Let's hope the winter comes and goes and maybe this will be a good excuse to open the pool early!


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