What to Do After a Hard Freeze: A Pool Owner's Checklist

South Texas freezes don't last long. A cold front blows in, the temperature drops into the 20s for a night or two, and by the weekend it's sunny again. The pool looks fine, and it's tempting to flip the breaker and get back to normal.

But freeze damage often hides until the ice melts. A pump housing can crack overnight and not leak a drop until water flows through it again. This checklist walks you through the safe way to bring your pool back after a hard freeze, from the first look outside to the last water test.

Why the days after a freeze matter

San Antonio's average first freeze arrives around November 30, according to KSAT's review of local weather records, and Hill Country towns like Boerne and Canyon Lake usually get theirs in early to mid November. Every so often a long cold snap shows what can go wrong. During the February 2021 winter storm, San Antonio International Airport dropped to 9 degrees, and the National Weather Service recorded more than four days below freezing. Burst pipes and long power outages followed across the region.

A fiberglass pool shell handles cold weather well. The parts that crack are the ones that hold small pockets of water: the pump, the filter, the heater, valves and above-ground plumbing. Water expands as it freezes, and that expansion splits plastic and metal. As Pentair puts it, cracks in frozen pipes and lines won't leak until they start to thaw. That's why the order of the steps below matters.

If you followed a freeze-prep routine before the cold front, such as the one in our guide to protecting your fiberglass pool during a Texas freeze, this checklist picks up where that one ends.

Step 1: Let the ice melt on its own

If a skin of ice formed on the pool, leave it alone. Leslie's tells pool owners not to break apart ice sheets on their own, and POOLCORP's advice is to leave ice undisturbed. In our climate it's almost always gone by the afternoon.

The same patience applies to the equipment pad. Hayward recommends waiting for any ice that has formed to melt naturally before you restore power. Give the sun a few hours to do the work.

Step 2: Inspect the equipment before you restart

Before you touch the breaker, walk the equipment pad with the power off and look closely. Pentair notes that anything made of plastic is the most likely to crack. Here's what to look for:

• Pump. Check the housing, the lid and the drain plugs for cracks. A cracked pump housing usually means replacing the pump.
• Filter. Look around the tank, especially near molded seams and threaded fittings, and around the pressure gauge and air relief valve.
• Heater. Look for cracks or water around the cabinet.
• Valves and pipes. Check every above-ground pipe and valve body for splits and white stress lines.
• Salt cell and automation. If you removed the salt cell or opened drain plugs, reinstall everything once the ice has melted. Check that timers and the freeze protection setting still work after any power outage.

If you find damage, take photos and note the part names or model numbers before calling for service.

Step 3: Restart slowly and watch for leaks

Once temperatures are above freezing and everything looks intact, it's time to bring the system back:

1. Close all drain plugs on the pump, filter and heater.
2. Open the air relief valve on top of the filter.
3. Turn the breaker back on and start the pump at a normal speed. Close the air relief valve once a steady stream of water comes out.
4. Watch the equipment for several minutes as it comes up to full pressure. Check fittings, unions and the pump lid for drips or spray.

If you see a leak, shut the system off and call a pool professional. Pentair warns that running equipment before a professional has assessed the damage may cause further harm.

Step 4: Check the heater before you fire it

Heaters deserve their own look, because the heat exchanger holds water and is costly to replace. If water pours out of the heater when the pump starts, the heat exchanger is likely damaged, and the heater should stay off until it is serviced. If everything is dry, run the pump for a while first, then turn the heater on and watch it through a full startup. Error codes or unusual noises mean it's time for a service call. If you're weighing a replacement, our guide to gas, heat pump and solar pool heaters compares the options for our climate.

Step 5: Test and rebalance the water

If the power was out, the pool may have gone a long stretch without filtration or sanitizer, and many salt chlorine generators slow down in cold water.

Pentair's advice after a power loss is to run the pump and filter for about an hour, then test the water and rebalance as needed. After a long outage, you may need to super-chlorinate to bring free chlorine up to at least 10 ppm. Empty the skimmer and pump baskets and run your cleaner to clear out debris.

Step 6: Keep an eye on things for the next few days

Some freeze damage takes time to show. Over the next several days, watch for:

• A water level that drops faster than normal evaporation would explain.
• Wet spots or soft ground between the pool and the equipment pad.
• Air bubbles coming out of the return jets, or a pump that loses prime.

Any of these can point to a crack in buried plumbing or a fitting.

When to call a professional

Call for help if you find a crack, a leak, a pump that won't prime or a water level that keeps dropping. Don't drain the pool to look for a problem. Pentair notes that fiberglass pools should never be left empty.

If your pool is a Staycation pool, see our warranty page for how to request service. For older pools, our pool renovation team can help you decide what to repair and what to replace. It's also worth calling your insurance agent. The Texas Department of Insurance suggests asking your agent what your policy covers for sudden water damage, and notes that some policies may not pay for frozen pipe damage if the pipes weren't protected.

Planning a new pool? Build for the cold snaps

A well-planned pool makes freeze season easier. Keeping above-ground plumbing short and adding automation with freeze protection both help. On Hill Country lots, such as those we build on in Boerne and Garden Ridge, we plan the pool and equipment for the site from the start. If you're thinking about a pool for next summer, schedule a free consultation and we'll walk you through the options.