Your pool's freeze protection is an electric pump being told to run. When a freeze takes the power down with it, the pump stops and the protection stops with it, and water left standing in the pump, filter, heater and pipes can freeze and crack them. The manufacturers' own manuals are clear about the limit and the fix: freeze protection is meant for short freezes, and for a long one Pentair and Hayward say to drain the equipment before it arrives. Here's how each piece drains, straight from those manuals, and which steps are yours and which are ours.
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Pool freeze protection is an automation setting that turns the pump on when the outdoor air sensor reads cold, so water keeps moving through the equipment instead of sitting still and freezing. Our guide to freeze protection settings shows where it lives on each brand. None of it can run without electricity.
The manufacturers say so plainly. Jandy's AquaLink RS manual describes freeze protection as "intended to protect equipment and plumbing for short periods of freezing only," and says it doesn't guarantee against damage from extended freezing temperatures or power outages. Hayward's ProLogic manual draws the same line: the automatic setting is for areas that only see occasional freezes, and for severe or extended freezing it says to drain the pump, filter, and supply and return lines before the freeze arrives.
Winter Storm Uri in February 2021 was the extended case. A University of Houston Hobby School survey found that 69% of Texans lost power at some point between February 14 and 20, for an average of 42 hours, and that the longest single stretch averaged 31 hours rather than short rotating outages. Close to 4.5 million homes and businesses were without power at the peak. For a pool whose only protection was its automation, that meant more than a day, on average, with no protection at all.
The manuals split freezes into two kinds, and the right move depends on which one is coming.
A short freeze with the power on: keep the water moving. Pentair's filter manuals say that in milder climates, when temporary freezing may occur, the filtration system should run continuously until freezing is no longer a concern, and Pentair's pump manual says to run the filtering equipment all night. That's exactly what freeze protection automates, and for most Houston cold nights it's enough.
A long freeze, or one you may face without power: drain. Pentair's cartridge and D.E. filter manuals say that if prolonged freezing is expected, the filter should be fully drained, and Hayward's ProLogic manual says to drain the pump, filter and lines before severe or extended freezing begins. A pump that isn't running isn't protecting anything, so a freeze you expect to ride out without power belongs in this second group.
In Houston, that means watching for two things in the same forecast: a hard freeze, which the National Weather Service defines as 28°F or lower for an extended period, and a real chance the power won't hold. Draining means no circulation and no chlorine until you restart, which is a small price next to a cracked housing. Our Houston hard freeze playbook covers the forecast and the days around it; this post is the drain side.
Do this before the freeze arrives, and turn the power off first. Pentair's pump manual starts its freeze steps with shutting off the pump at the circuit breaker, and that matters more than it looks: if you drain a pump and the power comes back with freeze protection still switched on, the panel can start a pump with no water in it, and Pentair says a pump run dry damages its mechanical seal.
| Equipment | What the manufacturer says to do | Who |
|---|---|---|
| Pump Pentair WhisperFlo | Power off at the breaker. Remove the two thumb-twist drain plugs from the pump housing and store them in the pump basket. Cover the motor against rain and ice, but never wrap it in plastic, and never cover it while it's running or may run. | You can |
| Sand filter Pentair Triton | Backwash, shut the pump off and open the manual air bleeder. Set a multiport valve to WINTERIZE (or remove a slide valve's piston). Remove the drain plug at the bottom and store it, drain the piping, and cover the filter with a tarp. | You can, if you know the valve |
| Cartridge or D.E. filter Pentair Clean & Clear Plus, FNS Plus | For prolonged freezing: fully drain the filter and remove the cartridges or grids, storing them and the drain plug where they won't freeze. That means opening the filter, following the manual's disassembly steps exactly. | You, if you clean your own filter; otherwise us |
| Gas heater Pentair MasterTemp | Power off to the heater and pump, gas valves closed, inlet and outlet unions disconnected and the heat exchanger drained, water pressure switch removed and its port plugged. Pentair's guide says to shut down and winterize when air temperatures are expected below 32°F. | Us: gas valves and opened plumbing |
| Heat pump Pentair UltraTemp | Disconnect the inlet and outlet unions completely and position the plumbing so all the water drains out. Cover only the top; don't wrap the sides in plastic. | Usually us |
| Salt cell Pentair IntelliChlor, Hayward ProLogic | Hayward says the cell and flow switch are damaged by freezing water just as the plumbing is. Pentair's winterizing steps drain the pump, filter and lines, then remove, clean and store the cell. Hayward says the control box itself handles winter weather and stays put. | Usually us |
| Pipes | Pentair's sand filter steps include draining the system piping, and Hayward's include the supply and return lines. Clearing lines with air is where the manuals get stern (below). | Us |
Blowing out the lines is a cold-climate winterization, and the manuals attach their strongest warnings to it. Pentair's filter manuals say that if you use compressed air, the filter's air relief valve must be open first, because trapped air can launch the lid with deadly force. Pentair's heater guide limits air purging of the heater, pump, filter or piping to a low-pressure, high-volume blower under 5 PSI, warning that compressed air can make components explode. An ordinary air compressor is the wrong tool. If your lines need clearing, that's a job for us, done in daylight before the front, not with a flashlight after the power's gone.
If you didn't drain and the power goes out mid-freeze, the pump is the piece most owners can still deal with quickly: breaker off, both drain plugs out, plugs into the basket. Switching the breaker off first is the important part, because it stops the pump starting dry when the power comes back while you're asleep. If the plugs won't turn, don't force them; leave the pump and call us once it's safe to.
If the power comes back while it's still freezing and you didn't drain anything, go and look at the pad. Is the pump actually running, and does the panel show freeze protection working? IntelliCenter, for one, shows Freeze Protect Active on its home screen. A tripped breaker or a pump that has lost its prime can leave you unprotected with the lights back on. Keep the water level up as well: freeze protection that switches on with the water below the skimmer just runs the pump dry. Why a pump loses prime is in our guide to a pool pump losing suction.
Restart in reverse, and don't let anything run empty. Put the pump's drain plugs back and fill the pump pot with water before it starts. Reinstall the filter's drain plug and cartridges or grids, and move a sand filter's valve off WINTERIZE. For the heater, Pentair's guide is explicit: if it was drained for freezing, don't turn it on until water is circulating through the system. A heat pump's unions go back on first, then the filter pump runs and you bleed the air out, and only then does the heat pump's breaker go back on.
Then walk the pad before you trust it: cracked pump or filter housings, split fittings, water where there shouldn't be any. The full order is in our equipment restart sequence. If something cracked, our pool pump repair and pool equipment repair teams handle it. Know this before you call, though: Pentair's pump manual says freeze damage isn't covered under warranty, and its heater guide says letting the heater freeze voids the warranty.
No. Freeze protection works by running the pump, and the pump needs electricity, so both stop together. Jandy's manual says freeze protection is meant for short periods of freezing only and doesn't guarantee against damage from extended freezes or power outages. If a hard freeze and an outage look likely together, drain the equipment beforehand.
Pentair's steps: shut off the pump's power at the circuit breaker, remove the two drain plugs from the pump housing and keep them in the pump basket, and cover the motor against rain and ice without wrapping it in plastic. Leave the breaker off until the plugs are back in and the pump pot is full of water again.
No. For a short freeze with the power on, Pentair's manuals say to keep the filtration running, and that's what freeze protection does. Draining is for prolonged freezing, and for any hard freeze you may have to ride out without power.
Not with an ordinary compressor. Pentair's heater guide limits air purging to a low-pressure, high-volume blower under 5 PSI because compressed air can make components explode, and its filter manuals say to open the air relief valve first. Clearing lines is a technician's job.
If you drained anything, keep the breaker off until the plugs are back and the pump pot is full, because a pump run dry damages its seal. If you didn't drain, check that the pump restarted and freeze protection is working. Then look for cracked housings and leaks before you run the heater.
Not for the Pentair equipment we checked. Its pump manual says freeze damage isn't covered under warranty, its MasterTemp heater guide says letting the heater freeze voids the warranty, and its UltraTemp heat pump manual says failing to winterize properly will void the warranty.
We'll show you where your breaker and drain plugs are, check your water level and freeze protection, and take care of the steps that need a technician, like the heater and the lines, when a hard freeze and an outage look likely together. Licensed, insured, serving Cypress and Greater Houston.