How to Keep Your Hot Tub From Freezing Through the Winter

Michael Keenan


Hot Tub Maintenance

I love having a dip in the hot tub when it’s winter! I know it’s not for everyone but for those who want to keep their hot tubs running through the colder months, you need to think seriously about stopping it from freezing.

Fortunately, there are some practical steps you can take to keep your hot tub from freezing up. This article will cover how to use freeze protection, keep the hot tub active, thaw out frozen pipes, as well as when it might be necessary to winterize your spa.

Whether you live in an area with mild winters or harsh ones, this guide is full of helpful tips and tricks on how you can make sure your hot tub stays warm all winter long.

A frozen hot tub is not only inconvenient because it cannot be used, but also because the water will expand in the pipes when it freezes and may cause equipment to get damaged.

If you don’t want to incur even more expenses, you should take the required steps to prevent your hot tub from freezing.

how to keep hot tub from freezing

Quick Answer:

Keeping your hot tub from freezing in winter can be a challenge, but it’s certainly doable! To prevent it freezing, you’ll want to use freeze protection mode if available, keep the hot tub active by running the jets regularly and invest in a good spa cover.

If the water has already started to freeze, try thawing out the pipes with warm water and introducing some heat into the spa. As a last resort, consider winterizing the spa which involves draining the water and blowing out all residual water from the pipes. Keep reading for more details ….

Freeze Protection for Your Hot Tub

One of the best ways to prevent your hot tub from freezing is to use freeze protection. If you have a new spa or it has an updated design, it is likely to have a freeze protection mode.

This is an intelligent and efficient mode where a sensor detects if the temperature has dropped under a certain degree. If yes, the sensor triggers the pump to come on and initiate circulation.

If your spa controls do not already have a freeze protection option, then you likely have to get equipment that will do this for you. Give your spa manufacturers a call and they may be able to offer you a good deal.

ice crystals forming in winter

Keep the Hot Tub Active

As long as the tub is active and all the pipes have water running through them, you should be able to prevent the pipes from freezing in the winter months.

It is advisable to open all the jets up so there is a constant circulation in the pipes.

Even if the water is not heated, as long as it is moving it should be fine. If the spa equipment is under a closed skirt, then the running pump will also generate some heat and will help prevent the water from freezing.

You can even set a timer for the jets to turn on for a few minutes every hour or so when the mercury drops. If you live in an area that experiences especially harsh winters, you may need to keep the jets running continuosly.

Get Creative With Insulation

First things first – I hope you have already invested in a good, insulated spa cover? Seriously, the number of people who don’t use spa covers always amazes me.

But, you can take things further using any kind of insulation. Think about it. Extra insulation will save you money if you run your hot tub through the colder months. There’s no such thing as too much insulation!

Think about using slab insulation that sits on top of the cover. What about the sides? If possible wrap the sides in insulation wrapped in plastic. Just like a hot water jacket on a household boiler. This can save energy – money and environment!

fibre insualtion

Thaw Out the Frozen Pipes

If you notice that the water has already started to freeze, it is possible to thaw the water out to prevent further damage. This is, of course, if the water has not frozen too much and there is still space in the pipes for it to expand without the equipment breaking.

You can introduce some hot water into the spa to thaw out the pipes. Even submerging the frozen pipes in warm water will help thaw it out, but do this slowly so that the sudden temperature difference does not cause the pipes to burst.

If you are an outdoors enthusiast and have a large tent handy, then you can even cover the hot tub completely with the tent. In a few hours, the tent should be able to insulate the spa and cause the frozen water to thaw out.

If the equipment has already been damaged or you notice cracked pipes, do not use any electrical heating (including the spa’s pump). It is best to call for professional help so that you can care for the situation with utmost safety.

Did those pipes freeze? Think you might have a leak in your hot tub? See that guide for some help.


This is the alternative. If you don’t plan on using the hot tub much during the winter, you should consider winterizing your spa. This option has been reserved as the last resort simply because winterizing the spa is time-consuming and it also means you won’t be using the spa too regularly.

It is an option best suited for those who use the spa only in the summers or if this is a spa in a vacation home that stays largely inactive through the year.

Winterizing the spa would involve draining the tub of all water, then blowing all the residual water out of the pipes to ensure that everything is truly dry. Be sure to read my full guide at the link above!

Once this is done, you can put the spa cover back on and leave it as it is until you want to refill the spa again after a few months. Winterizing will protect your tub and you don’t need to worry about it until you plan to open it again after the cold weather. When the time comes, see my guide on cleaning a hot tub that’s been sitting.

Final Thoughts

Remember that no matter what method you use to prevent the spa water from freezing, you will need to cover the spa not only to keep the water from freezing but also to avoid impurities like dust entering the water in case it is an outdoor tub.

A good spa cover will be able to insulate the tub well and is a must especially if you live in a cold region. If the surface of the water freezes, it will not allow heat to pass through the water and may accelerate the freezing process.

So no matter what you do, invest first in a good spa cover.

If you do notice that water has already begun to freeze, there are ways to thaw out the pipes without damaging them further. Slowly introducing hot water or using a tent for insulation can help unfreeze frozen water safely.

Winterizing your spa is a good idea if you’re not planning on using the tub through a cold spell.

Me? I love to keep it working throughout the winter months. I use it more in winter than summer! Just remember to keep a regular maintenance schedule whatever the time of year. Thanks for reading!

michael keenan author

Author - Michael Keenan

I'm Michael Keenan the owner and creator of the Outdoor Care Guide. I'm a trained horticulturist with over 30 years of experience in pool care, plant care, and landscape care! Seemed like a good idea to share - I think I can make your life easier and save you some time and money!