Why a Year-Round Pool Is More Vulnerable Than a Winterized One
A pool in Michigan gets drained below the returns, blown out, plugged, and covered every fall; there's no water in the pipes to freeze. A pool in San Antonio, Lake Havasu, or Ocala stays full and running all winter, and that's what makes it vulnerable.
Water in an exposed pump housing, filter, heater, or plumbing line will freeze if the temperature stays low enough for long enough, and when it does it cracks whatever is holding it. Year-round pools aren't built to be drained, and most owners have never had to think about it.
The February 2021 Texas freeze was the cautionary example. Days of sub-freezing temperatures combined with widespread power outages left equipment pads across the state with cracked pump housings, split filter tanks, and broken heater manifolds. Pool companies spent months on repairs. The same thing can happen on a smaller scale any winter in Arizona's high desert, North Texas, or North Florida.
How Freeze Protection Works
The principle is simple: moving water doesn't freeze easily. Freeze protection runs the pump when the air temperature drops so water keeps circulating through every pipe and piece of equipment.
| Equipment | How It Protects |
|---|---|
| Automation system with freeze protect | Temperature sensor turns the pump on automatically below a set point (usually 34–38°F) |
| Variable-speed pump with freeze mode | Built-in sensor runs the pump at a set RPM when it gets cold |
| Mechanical timer only | No freeze protection; you must switch the pump on manually |
| Heater | Some heaters have freeze protection that fires the heater briefly; check the manual |
If you have automation or a variable-speed pump, confirm freeze protection is enabled and the set point is correct; many ship with it off. If you only have a mechanical timer, you're the freeze protection.
Before the Freeze
- 1Confirm freeze protect is on and check the sensor reading in your automation app if you have one.
- 2If a multi-day freeze is forecast, set the pump to run continuously. Don't rely on the sensor.
- 3Open every valve so water moves through all lines, including the spa, water features, and solar if you have it.
- 4Insulate exposed plumbing, the pump, and the filter with foam pipe wrap, towels, or blankets. Keep the pump motor vent clear.
- 5Cover the heater with a blanket if it's not running; cold air through an idle heater is how manifolds crack.
- 6Top off the water so the skimmer keeps drawing.
During a Multi-Day Freeze
Keep the pump running around the clock. A few days of continuous run costs far less than one cracked filter tank.
Check the equipment pad twice a day for ice on the pump lid, dripping unions, or a pump that's running but not moving water (a frozen line). If water stops moving, shut the pump off; running dry burns the motor.
If the Power Goes Out
This is the scenario that caused most of the 2021 damage. Without power, nothing circulates. If the outage looks like it will last more than a few hours in sub-freezing weather:
- Shut off the breaker so the pump doesn't start dry when power returns
- Open the drain plugs on the pump, filter, and heater to let water out
- Remove the pump lid and pump basket
- Open all valves and unions so pipes can drain toward the equipment
- Cover everything with blankets
This is a partial winterization done in a hurry, and it saves the equipment. For the full procedure, see how to winterize a pool.
After the Freeze: What to Inspect
Once temperatures are back above freezing:
- 1Walk the equipment pad before turning anything on. Look for cracks in the pump housing, filter tank, heater cabinet, and PVC.
- 2Reinstall drain plugs and the pump lid.
- 3Prime the pump and start it. Watch every union and fitting for leaks for the first 10 minutes.
- 4Check filter pressure; a sudden change can mean a cracked grid or cartridge.
- 5Run the heater and watch for water from the cabinet.
- 6Test and rebalance the water.
What Freeze Damage Costs to Repair
| Repair | Typical Cost (2026) |
|---|---|
| Cracked pump housing (new pump) | $700–$1,800 |
| Cracked filter tank | $800–$2,000 |
| Heater manifold or heat exchanger | $500–$1,500 (often replace the heater: $2,500–$5,500) |
| Split PVC on the equipment pad | $150–$600 |
| Cracked salt cell | $500–$1,200 |
After a regional freeze, every pool company is booked for weeks and parts run short. See pool pump repair cost and pool heater repair cost for more on the two most common casualties.
Browse Pool Service Companies in Freeze-Exposed Markets
Year-round pools that see hard freezes most often: Fort Worth, TX · San Antonio, TX · Corpus Christi, TX · Lake Havasu City, AZ · Oklahoma City, OK · Tulsa, OK
More high-demand cities:
- Sarasota, FL · Naples, FL · Fort Myers, FL · Tampa, FL · Ocala, FL
- Lake Havasu City, AZ · Corpus Christi, TX · Fort Worth, TX · San Antonio, TX
- Bakersfield, CA · Fresno, CA · Oklahoma City, OK · Tulsa, OK
Or by state: Texas, Arizona, Oklahoma, Florida, Nevada, California.
Bottom Line
Turn freeze protect on, run the pump through the freeze, wrap what's exposed, and drain the equipment if the power dies. Not sure your system is set up right? Find a pool service company near you and have them check it before the first cold snap.