Winter is one of the best times of year to own a hot tub, especially if you live in a northern U.S. state. You might enjoy a lovely vista of snow covered trees and mountains over the steam rising from the warm water of your spa as the jets massage your tired muscles. Winter comes with challenges though, and two are worrying about the pipes in your home and taking steps to keep your hot tub from freezing. But, while freezing pipes may be a serious concern for homeowners in cold regions, well-insulated hot tubs rarely pose a problem in winter. In fact, if you own a Caldera® spa you don’t have to winterize your spa at all unless you leave for an extended trip.
Caldera Spas Stay Warm All Winter, Keeping Your Hot Tub From Freezing

One common way to help prevent a home pipe from freezing is to open a faucet slightly to let a trickle of water flow through. Flowing water doesn’t freeze as quickly as still water, and it may melt any ice starting to form in a pipe. Keeping that in mind, consider how a home hot tub is engineered.
The latest high-tech hot tubs are equipped with freeze protection—circulation jet pumps and heaters that are activated when temps drop to 40 degrees Fahrenheit to keep the water hot and flowing. A Caldera Spa, for instance, is equipped with an EnergyPro® circulation pump that periodically pumps the water through the filters to help keep it fresh, as well as an EnergyPro® heater that keeps the water well above the freezing point.
Caldera spas have additional features that not only keep the spa warm through winter, but also provide energy efficiency. Features include:
- A FiberCor® insulated cabinet. Top-quality insulation protects the spa’s machinery and water from the effects of cold weather.
- A fitted, insulated hot tub cover. An insulated cover made specifically to tightly fit your spa model helps prevent heat from escaping, reducing your energy costs and keeping the water from freezing. Since spa covers are heavy-duty, most can withstand a few inches of snow accumulation before cleaning off.
- A Poly Sheet bottom seal that helps keep the warm air in the cabinet from escaping. The bottom seal of Caldera Paradise® Series and Vacanza® Series spa helps to keep heat from escaping from below and when the spa is on a concrete pad or deck it provides another layer of insulation. Utopia® Series spas include an ABS base pan with a ribbed pattern, which is designed to reduce contact with the freezing ground.
While these features will help keep your hot tub from freezing in cold weather, you might want to take extra precautions to prepare your hot tub for winter. You might even consider winterizing your spa, but that’s a big step that will cause you to miss out on the hydrotherapy benefits of your hot tub for a few months.
How to Determine if You Need to Winterize Your Hot Tub

If you’re going to be at home most of the winter, you might not want to go through the trouble of winterizing your spa, which simply means shutting it down. Closing your spa for the season will prevent you from enjoying a cold winter’s night in the warm water of your spa, and you’ll miss out on all of the wellness benefits your hot tub provides. But if you own a summer vacation home with a spa and won’t return to it until spring, or if you’ll travel for weeks on end during the winter, winterizing is smart.
If, however, your plans include only a short vacation, winterizing isn’t necessary. The Connextion® Hot tub Monitoring System, available with Caldera spas, can give you piece of mind while you’re away. Connextion allows you to check and control your hot tub settings remotely, and even lock your spa from far away. The best part is that the system will also notify you and your dealer if it detects an issue that needs to be handled, ensuring that your hot tub is in good hands until you return.
How to Winterize Your Spa to Keep Your Hot Tub from Freezing

Winterizing your spa should happen before temperatures drop below freezing. Draining the water while temperatures are still relatively warm will ensure that trace amounts don’t freeze in the spa or its pipes afterward.
To winterize your spa, you’ll need the following equipment:
- A garden hose to direct the water you drain.
- A wet/dry vacuum cleaner to remove residual water from the bottom of the spa and its pipes.
- Towels or rags to thoroughly clean and dry the shell, seats, and bar top.
- Propylene Glycol, a non-toxic antifreeze*, to prevent spa pipes and machinery from freezing.
- A funnel for directing the antifreeze you pour into hard-to-reach openings.
Stagnant water can allow for the growth of bacteria and algae. In order to avoid microbes lingering in the piping of a dormant spa, make sure the water is clean before you drain it. It’s a good idea to use draining a hot tub for winter as a chance to clean the shell, bar top, and filters too as this will make refilling it quicker when you return.
How to Winterize Your Hot Tub
- Turn off the power to your hot tub. Find the circuit breaker box near the tub and turn the GFCI breakers to the off position. Since this is a long term shut down, you may wish to turn the circuit breaker on your home’s main panel off as well. If you cannot find these breakers contact your local dealer or electrician for assistance.
- Drain the spa water. Unscrew your hot tub’s drainage plug and attach the garden hose. Place the far end of the hose in a place where the water can safely drain away from your home’s foundation. If you have a submersible pump, you can use it to speed up this process.
- Remove filters, cartridges, accessories. Remove, clean, and dry filters, and then store them in a warm, dry place. If your spa has detachable pillows and spa-side accessories, remove and store them as well. Discard any chemical cartridges in the spa.
- Remove remaining water. Once the water has stopped flowing from the hose, there may still be several gallons left inside the spa that can freeze and cause damage. Use the wet/dry vacuum to remove water remaining in the bottom of the tub and from the jets, filter stand pipe, and any other opening in the hot tub.
- Add antifreeze. Replace the spa’s drain cap, and then dilute the antifreeze as directed on the bottle. Using the funnel, pour a small amount of antifreeze into jet openings, the filter standpipe, and water feature orifices.
- Clean the spa. Use towels or rags to clean the shell, bartop, and other spa surfaces with approved cleaners.
- Cover your hot tub. Replace your hot tub cover and securely latch it in place. Place two pieces of plywood across the top of your spa to prevent damage that might occur as a result of accumulated snow, and then cover with a tarp.
Caldera spas are engineered for reliability and everyday use—all year long. So, caring for your hot tub to keep it from freezing in winter involves very little effort. Your local Caldera spa dealer is well-trained and will be happy to help answer any questions you might have.
Caldera spas are sold and serviced by a global network of dealers dedicated to customer satisfaction. Enjoy the best year-round support for your hot tub or find the perfect spa to keep you warm all winter at your local Caldera dealer
*Important: Propylene Glycol is not the same antifreeze that is used in a car, which is toxic Ethylene Glycol.