How-To Guides | Winterizing & Cold Weather Prep

Winter is a wonderful season to use a hot tub. The hot water & massage breathes life back to frozen feet and aching joints. Instead of winterizing the spa for the cold, why not make the most of your investment and enjoy it?

large snow covered cabin with steaming bubbling hot tub

New, energy-saving hot tubs stay hot and ready all winter, without adding to your electric bill. Insulation and a quality spa cover keep the heat in, so there is no need to winterize with proper upkeep.

Most freeze damage is caused by water left in the spa. Draining the spa the right way to protect it from freeze damage is important. If you do leave your spa powered down during the winter, follow our step-by-step  Guide to Close & Winterize your spa.

snow covered hot tub on porch with wreath and stacked firewood

Pre-Winter Prep

Don’t wait until freezing rain, snow, or other winter storms hit to maintain your tub. Draining, cleaning, and refilling the spa are much more difficult tasks when the weather is nasty.

Water Maintenance

Use Spa System Flush to clean the plumbing before draining and refilling the hot tub by the end of autumn. System Flush will clear the pipes of built-up oils, grime, and scale, making winter water chemistry simpler.

Keep a chemical care schedule to minimize time spent on water care in cold weather. Take notes of the treatments you use in a Spa Log Book or notebook for easy reference.

Spa Cover and Cabinet

Check your spa cover for signs of wear in early fall. If your cover is not in good shape, replace it before the cold weather hits. Wear includes faded or cracked vinyl, heavy foam cores, tearing seams, and handles. Not only will a new cover insulate better, but the lighter weight will make it easier to open and close.

hand securing spa cover buckle lock

If cover latches are broken, replace them with new buckles & locks. Straps should be snug and secure. Straps form a tight, steam-blocking seal against the spa shell.

Clean the cover using ecoTUB Spa Clean, and treat the top and bottom with 303 Protectant. 303 is the only product we recommend for protecting vinyl. Other vinyl products contain harmful silicone oil and petroleum distillates.

woman in respirator mask sealing wood hot tub cabinet

If you have a wooden spa cabinet, treat the wood each fall. Use a weatherproof sealer or linseed oil to prevent the wood from warping due to moisture. For synthetic cabinets, remove dirt and other residues using ecoTUB Spa Clean.

Cold Weather Maintenance

Once temperatures drop, hot tub use is even more fun. If you are closing your tub, look out for potential issues that could cause freeze damage.

snow covered cabin with blue hot tub on porch

Energy Efficiency

An inefficient spa can be costly to run in winter. Since most heat is lost through the top of the spa, a high quality spa cover is very important.

Reduce energy costs and prolong the life of your cover with a spa bubble blanket. The floating blanket sits on the water's surface, reducing steam up to 95%.

woman placing thermofloat floating spa blanket on hot tub water

Maintain a constant water temperature. Keeping the spa cool and raising the temp before use uses more energy and puts a strain on the pumps. A higher temp protects the tub from freezing as well. In the event of power loss, it takes longer for 100°F water to freeze than a lower temp.

Air induction lines increase jet pressure when the spa is in use, but also lower the water temperature. After each use, close the air induction control knobs.

Avoiding Spa Freezing

Monitor the water level of the spa regularly. Leaks can lower the water level enough to stop spa pumps and heating, causing potential freezing conditions.

icicles hanging from power lines

In the event of a power outage, keep the spa cover in place to keep the heat sealed in. If the power is out for a while or it's very cold, run a generator to keep the pumps cycling. Follow the winterizing steps below if a generator is not available to run the spa.

Winterizing Guide - Closing your Spa

Sometimes winterizing is the only practical solution to a spa that may sit unused for months during freezing weather. Emptying the spa is not enough. As much as 6 gallons of water can remain in the pumps and plumbing after draining. This water could easily freeze, expand, and crack valuable plumbing and equipment.

cracked pipe from hot tub freeze damage

If you can't winterize or have an in-ground spa, a spa technician can close the hot tub for you. Look for an experienced technician that guarantees their work against freeze damage.

To Winterize, You Will Need:


  1. Add Spa System Flush to the spa before draining, thoroughly cleaning the plumbing to avoid bacteria and mold growth.  Allow to circulate for a few minutes (up to overnight).
  2. Shut the power off to the spa at the service panel and disconnect the breaker.
  3. Fully drain the spa. A Shake-A-Vac or drain pump may be used to speed draining and remove grit and debris from the foot well.
  4. Remove the filter(s). Any filter older than a year should be discarded. Clean newer filters using Filter Cleaner, dry and store them in a clean, dry location. How to Clean your Filters
  5. If you have a blower, unplug the heater at the pack or disconnect the heater terminals. Power the spa on & with the spa cover on, turn the blower on in 15-30 second intervals. Repeat until all water is purged from the air lines. Turn the spa off at the panel and breaker again.
  6. Loosen unions and drain plugs, allowing water to drain from the pump(s) and heater. Retighten all except the pump discharge unions.
  7. Close the air control knobs for your jets. Open each jet all the way (if you have adjustable jets). Use a wet-vac to blow air into each jet face, moving around the spa from top to bottom twice.
  8. Clean the spa shell with a non-foaming, pH-balanced cleaner such as ecoTUB Spa Clean. Rinse all spa surfaces thoroughly.
  9. Use a wet-vac to remove any leftover water in the foot well and seats.
  10. With a soft, absorbent towel, dry all surfaces of the spa. Include the inside of the filter area, cup holders, ice bucket, etc.
  11. Apply Gel Gloss or 303 Aerospace Protectant to the spa shell, and clean and protect the spa cover.
  12. Dilute non-toxic antifreeze as directed on the bottle. Pour one gallon prepared antifreeze into the filter area, and one gallon into each pump discharge. Tighten pump discharge unions.
  13. Replace cabinet panels and secure all cabinet screws or latches, including locking the cover buckles.
  14. If winter storms are severe in your area, use ratcheting straps for extra protection against the cover blowing away.
  15. Cover the spa with a CoverAll or weighted tarp to keep water from seeping back into the spa.

snowy cabin with wood-fired round wooden hot tub

Winterizing a Wooden Hot Tub

Wooden hot tubs are winterized differently due to their organic nature. The floorboards and wood slats, or staves, must stay saturated with water to avoid shrinkage and leaks.

Drain the wood hot tub of water except for 2-3” of water in the bottom. IMPORTANT: Add non-toxic RV antifreeze to prevent freeze damage which could otherwise split the wood floorboards.

Follow the above instructions for blowing water out of the jet lines or blower, if present. Purge all water out of the pump. Cover and tarp the tub, checking monthly to make sure there are several inches of water in the tub.


Recently viewed