Pool Freeze Protection: Easy Steps Before Frisco’s Next Freeze

Do Pools Freeze in the Winter in Frisco?

The pool itself almost never freezes solid here. Your equipment can freeze in one night, though, and that is where the repair bills come from.

A backyard pool holds thousands of gallons, and that much water gives up heat slowly. In a typical North Texas freeze, you might see a thin skin of ice on the steps, and that’s about it. The trouble is the water outside the pool. The pump, filter, heater and above-ground PVC hold only a few gallons each, and they sit out in the wind.

Water expands by about 9% when it freezes. Inside a closed pump housing or filter tank, that pressure has nowhere to go, so the plastic splits. Pentair notes that a frozen pipe often won’t leak until it thaws, so a crack can hide for a day or two.

That’s why pool freeze protection is really about circulation. Moving water carries heat from the pool into the pipes and is much harder to freeze. If something does crack, get freeze-damaged pool equipment repair in Frisco before you restart. Running cracked equipment usually makes the damage worse.

How Often North Texas Freezes, and for How Long

DFW Airport averages 29 nights at or below 32°F each winter, mostly in December and January. The bigger risk is the rare freeze that lasts for days.

NWS records put the average first freeze at DFW on November 22 and the last on March 12. Most of those nights dip under 32°F for a few hours before sunrise, which a running pump handles easily.

January is the riskiest month, with 10.6 freezing nights in an average winter, and December is close behind at 8.1.

The long freezes are what break equipment. The longest stretch below freezing at DFW ran 295 hours, from December 18 to 30, 1983. In 2021, the 139-hour run followed a 93-hour stretch earlier that month. That adds up to 232 hours at or below freezing in one February. When the cold lasts that long, a few hours without flow is all the ice needs.

Should I Run My Pool Pump in Freezing Weather?

Yes. Once the forecast low drops into the mid-30s, run the pump around the clock until the air climbs back above freezing. Raypak’s heater manual says “continuous pump operation is a must” in freezing weather. Pentair tells owners without automation to run the equipment 24/7 until temperatures return to normal.

Don’t trust the schedule you set in September. A timer that shuts off at 10 at night leaves the coldest hours with no flow. Empty the skimmer and pump baskets that afternoon, too. Cedar elm and Bradford pear leaves pack them fast in late fall, and a choked basket cuts the flow freeze protection depends on.

How to Test Your Pool Freeze Guard Before the First Front

Trigger it on purpose on a mild day and watch the pump start. A freeze sensor nobody has tested is a guess.

A pool freeze guard is any sensor or thermostat that turns the pump on when the air gets cold. On automation systems it’s an air sensor wired to the control board. Older timer setups use a separate freeze thermostat in the timer box. Either way, it has to read the right temperature and switch the right circuits.

A Plano homeowner caught what happens when it doesn’t on his own security camera. He told WFAA his freeze stat never kicked on overnight. After he thawed the pump and switched it on, ice still in the filter built pressure, and the filter top blew off.

Pool Freeze Protection for Waterfalls, Spa Spillways and Exposed Pipes

Anything that sits above ground or holds still water freezes before the buried plumbing does. Give those spots extra attention the afternoon before a hard freeze.

Waterfalls and sheer descents often run on their own pump. If that pump isn’t in freeze mode, the line to the feature sits full of still water all night. Run the feature with the main pump, or have it assigned to freeze protection. A raised spa with a spillway needs flow too, since its plumbing climbs out of the ground into the wind.

Then walk the pad. Above-ground PVC between the pump, filter and heater sits right in the cold. So does the backflow preventer on an autofill or irrigation line, usually tucked in a side yard behind the fence. The City of Frisco’s cold weather tips tell residents to wrap exposed outdoor pipes and keep enough water in the pool. They also say to make sure pool freeze protection systems are working. Foam pipe sleeves work on straight runs, and an insulated cover fits the backflow preventer.

Why a Gas Heater Isn’t Pool Freeze Protection

Water moving through the heater is what protects it. Firing the burner during a freeze can damage the heater and does nothing for the rest of the pad.

It’s tempting, because the pool is cold and the heater is right there. Raypak’s RP2100 manual has a caution for exactly this. It says not to use the heater “for freeze protection” or to hold water just above freezing. The same manual warns that long runs with water below 50°F can seriously damage the heater. Raypak doesn’t warrant it against freeze-ups, either.

Hayward’s OmniLogic makes the call for you. In freeze protect, automated heating stops until the air warms up. During a power outage, the point is moot anyway. Most modern gas pool heaters need electricity to light and pump flow to close the pressure switch.

So leave the heater off and keep the pump running. Water flowing through the heat exchanger protects it like any other pipe. If the heater throws codes or drips after a cold snap, book gas pool heater repair instead of resetting it over and over.

What to Do If the Power Goes Out in a Hard Freeze

If the power is out and the air is below freezing, drain the equipment. Every pool freeze protection feature in the table above needs electricity. Once the pump stops, still water starts turning to ice.

It doesn’t take long. During Uri, AQUA Magazine described North Texas owners waking up to single-digit cold after four to five hours without power. Pumps and filters froze across the state. Don’t wait to see if the lights come back. Pentair’s winter storm guide covers most of these steps:

1. Switch off every pool breaker so the pump can’t restart into ice.
2. Open the filter’s air relief valve and take the lid off the pump.
3. Pull the drain plugs on the pump pot and the volute, the round housing around the impeller.
4. Remove the filter drain cap and the plug on the multiport or dial valve.
5. Open the drain plugs on the gas heater’s header.
6. Drop every plug in a zip bag and leave it on the pad.

If your pad sits lower than the pool’s water line, close the suction and return valves before you pull plugs. Otherwise the pool will drain through the open ports. A half-filled plastic jug in each skimmer also gives ice room to expand.

Restarting After the Thaw

Look before you flip a breaker. Wait until everything has fully thawed. Then check for split PVC, a cracked pump housing or a hairline crack in the filter tank. If the pump won’t hold prime or the volute seeps, call for pool pump repair before running it.

A Printable Pool Freeze Protection Checklist for Freeze Night

Print this and tape it inside the garage near the breaker panel. Run through it the afternoon a hard freeze is in the forecast, before the sun goes down.

Before Sundown

1. Check the forecast low and how many hours it stays below 32°F.
2. Set the pump to run 24/7 at a speed that moves water at every return.
3. Empty the skimmer and pump baskets.
4. Open the valves to the spa, waterfall and cleaner lines, and leave the main drain open.
5. Confirm freeze mode is on for every pump and feature that needs it.
6. Top off the pool to the middle of the skimmer opening.
7. Wrap above-ground PVC and the backflow preventer, but keep motor vents clear.
8. Turn the gas heater off, since Raypak’s manual says not to use it for freeze protection.
9. Disconnect and drain garden hoses, as the City of Frisco recommends.

Overnight and the Next Morning

1. Before bed, make sure the pump is still running and water is moving.
2. Look again at sunrise, when the air is usually coldest.
3. If the power drops while it’s below freezing, follow the drain steps above.
4. After an outage, wait for a full thaw and inspect everything before restarting.