Swimming Pool Blog
by Rob Cox, October 31, 2010
Protect your Sunbelt pool from freezing temps
For most pool owners in the US, winterization is not a common practice. In the more temperate regions of the country, swimming pools will be used less, chlorinated and filtered less, and sometimes all but forgotten. But many areas in the sunbelt, yes even in Florida and Texas, have cold nights where the temperature dips below freezing. When I was a young boy in northern Florida, during these cold nights my father would run the sprinkler and we would wake up to long icicles hanging off the palm trees.
Pool owners who watch the temperatures during the winter will do their best to keep the pumps running all night. If outside air temperatures reach 32 degrees for several hours, this could be long enough to freeze the water within the pump, filter, chlorinator or heater - often with disastrous and expensive results. Above ground PVC pipes also have little resistance to the expansive effects of freezing water.
Pipes that are below ground will be able to withstand short drops in temperature. For every day the temp is below freezing, the cold temps sink into the ground about an inch. For example pipes that are buried 12" below ground level may be able to stay liquid up to two weeks without damage.
Pool Heaters headers, especialy those made of cast iron, will crack before the more freeze resistant thermoplastics. It takes only a degree or two below 32 F to cause damage. Pump bodies and Filter tanks tend to be more resistant, but they have their limits as well. PVC piping tends to crack in a spider web fashion, with long cracks that can extend into valve bodies.
Here's some ways to prevent freeze damage to your pool equipment:
1. Run the filter pump whenever temps are forecast to be near freezing. If you have a booster pump for a pool cleaner or waterfall - these need to be running also. Two speed pumps can be operated on low speed, water does not need to move fast to be kept from freezing, it just has to be in motion.
2. All valves should be at least partially open to allow for some flow through all pipes and equipment.
3. Wrapping pipes with a heat coil or with heavy foam can prevent freeze damage, but be sure that all areas are receiving warmth.
4. Using freeze sensors is the high tech method. Attached to your timeclock or controller, a sensor will turn the pump(s) on automatically when temperatures head below 40 degrees. Make sure though, from year to year, that these sensors are still activating - a loose or broken wire can easily cause your peace of mind to fail.
5. Another alternative is to simply drain the above ground pool equipment (make sure timer clock won't turn pump on). Remove pump drain plugs, filter drain plugs, heater drain plugs, etc. Don't put antifreeze into your equipment, as it could damage seals and certain rubber compounds.
If your sunbelt pool freezes, follow these steps to thaw out pool equipment:
1. Shut off pump at the breaker or remove time clock trippers so that pump won't try to turn on with frozen water surrounding the impeller.
2. Place a large tarp or blanket over the equipment, and carefully place a small space heater underneath. Use a low setting and allow for some cross ventilation. Be careful that the blanket will not catch fire from the space heater. In a pinch, a handheld hair dryer can also be used. Be careful that water does not come into contact with the heater or hair dryer, as there is a risk of electrocution.
3. Carefully inspect the system before turning on the pump - checking for broken pipes or equipment. Make sure all water is thawed before starting pool pump.