Leslie's Freeze Protection Service
Owning a pool in climates that reach freezing cold temperatures can cause issues for pool and spa owners. This is especially true if they don't have any sort of pool freeze protection. During these temperature drops, water freezes and expands its volume by about 9%. This expansion can cause all kinds of issues for pool equipment and plumbing.

The expansion of freezing water causes intense pressure in pool equipment and plumbing lines. They often crack or break open under the pressure, resulting in costly repairs. Turning your pump and heater on when temperatures drop keeps water from becoming stagnant in equipment and plumbing. In turn, this can reduce, if not eliminate, the chances of freeze damage.
It sounds like a small number, but in the world of physics, it’s a powerhouse. When water transitions into ice, it expands its volume by approximately 9%. While that might not seem like much in a glass of water, inside the rigid confines of your pool’s PVC pipes, pump housing, or heater manifold, that expansion creates immense, outward pressure.
Because water is non-compressible, something has to give. Unfortunately, that "something" is usually your expensive equipment. This pressure can cause hairline fractures or even complete blowouts in your plumbing lines, leading to underground leaks and costly repairs that can put a real damper on your spring opening.
Keep It Moving: The Secret to Freeze Prevention
The best way to prevent your pool from turning into a giant ice cube is to keep the water in motion. Stagnant water is far more susceptible to freezing than water that is actively flowing.
- Run Your Pump: When a freeze warning is issued, your primary goal is to keep your filtration system running 24/7. Moving water generates friction and carries a small amount of latent heat, which is often enough to keep the temperature above the freezing point within the equipment.
- Don't Forget the Heater: If you have a heater, running it periodically during a deep freeze can provide that extra layer of warmth needed to protect the internal components.
- Automated Freeze Protection: Many modern pool automation systems come equipped with a freeze sensor. These "smart" systems automatically trigger your pump to turn on when the air temperature hits a specific threshold (usually around 38°F), ensuring you never have to worry about missing a weather update.
Choosing and Installing Freeze Protection Units
Leslie's carries several different types of Freeze Protection Units, so we're sure to have the one right for you. It's important to ensure the best fit for your pool system.
Freeze Protection Units allow pool and spa owners to set a desired temperature where their pump and heater will automatically turn on. Once the climate drops to the specified temperature, the Freeze Protection Unit kicks in. It turns on your pump and heater to keep the water moving, which will help prevent freeze expansion.
What If the Power Goes Out?
In the event of a winter storm and a subsequent power failure, you must act fast to protect your equipment. If the pump can't run, the best course of action is to "drain the brain." Turn off the power at the breaker and remove the drain plugs from your pump, filter, heater, and chlorinator. This allows the water to exit the equipment before it has a chance to expand and cause damage.
Don't let the winter weather put your pool plans on ice! By understanding the risks of expansion and staying ahead of the frost, you’ll ensure that when the sun comes back out, your pool is ready for another season of making a big splash.
If you’re unsure about your local climate's requirements or need a professional to inspect your freeze protection sensors, our team is always here to help you stay afloat! Learn more in the next section.
Leslie's Service and Repair
Have one of our trained service technicians come to your house, evaluate your pool, and determine the proper solution for your pool or spa.
Our Leslie's trained service technicians are licensed, bonded, insured, and are experts in their field. To avoid any hassle and ensure installation goes properly, our technicians will help you choose the right Freeze Protection Unit for your pool and install it, as well.
To make an appointment with one of Leslie's trained service technicians, visit our services page, or stop by your local Leslie's to request an appointment.
If you are looking for maximum protection from freeze damage, and you're ready to winterize your pool, we also carry a large selection of pool closing products. With a little help from Leslie's, it's easy to protect your pool and spa through the off-season.