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The last thing you want is for the water to freeze inside your expensive inflatable hot tub, damaging the pump and heater prematurely. So what’s the deal, is it safe to use a hot tub in winter?
Inflatable hot tubs can be used during the winter as long as the temperature remains above 40°F (4°C). For temperatures below 40°F, you’ll need a 4-season spa that has been specially designed to withstand freezing temperatures. Extra insulation and protection are important for hot tubs used in the winter.
In this article, I’m going to show you:
- How to prevent freezing by using effective insulation
- How to properly store your spa away during harsh weather
- The best 4-season hot tub for winter soaking
Can you use an inflatable hot tub in cold weather?
As long as you don’t live in an area where the winter falls below 40°F (4°C), then it’s fine to use an inflatable hot tub all year round.
But before you rush off to enjoy some winter hot-tubbing, it’s worth taking the time to understand how the cold weather will affect your hot tub. There are also a few things you need to do to protect your spa during the winter months.
It’s absolutely crucial that you use an insulating mat beneath your hot tub.
Without a mat, you’ll lose a ton of heat to the ground, which will make the motor work extra hard to maintain your chosen temperature, raising your electricity bill unnecessarily.
Even if it isn’t cold out, you should use a mat all year round anyway for protection as it’s all too easy to rip and tear the lining on inflatable spas.
These double-sided, non-slip puzzle mats are made from high-density EVA foam and simply interlock to hold in as much heat as possible. They even reduce noise too.
I recommend using the 1-inch (25ml) thick mats for maximizing insulation. The interlocking tiles fit together to cover 72 square feet (6.7 m2), which is plenty for an inflatable spa.
Unlike hard-sided hot tubs that have lots of insulation to trap the water’s heat, a huge amount of heat is lost through the sides of inflatable hot tubs.
Insulation jackets massively reduce heat loss, saving you money on your energy bill and putting less stress on the heater.
How hot can inflatable hot tubs get in winter?
While the maximum temperature for most inflatable hot tubs is 104°F (40°C), it’s important to understand how this is affected in cold weather.
If the air temperature outside is above 40°F (4°C), you should be able to reach and maintain your desired water temperature so long as the spa is sheltered from the elements and has good insulation.
At temperatures below 40°F (4°C), a standard inflatable hot tub will struggle to make it past 95°F (35°C), even with adequate insulation. And while the temperature dial might read above 40°F (4°C), the wind chill will certainly tell a different story.
Preventing the wind from blowing directly across your hot tub keeps it safe and protects from any debris carried by the wind. Constructing a simple enclosure makes it a lot easier for your hot tub to stay warm.
It’s also a good idea to invest in a thermal blanket that floats on top of the water. It reduces evaporation by up to 95%, which not only lowers electricity usage but prevents chemicals from evaporating too, saving you even more money.
Does it cost more to run an inflatable hot tub in the winter?
The cost of running an inflatable hot tub during the winters months is slightly more expensive. Expect to add around $10 to your monthly energy bill during the winter season. The running costs can be reduced by adding good insulation and enclosing the spa.
There are a couple more ways to run a hot tub economically during the winter. You can lower your electricity bill by having the filter cycles run during off-peak hours, reducing the spa temperature by 10°F (5°C) between uses, and leaving your hot tub on all the time.
It might sound counter-intuitive, but leaving your hot tub on all the time costs far less than reheating the water from cold every time you use it.
So whatever temperature you enjoy bathing in, lower it by 10°F (5°C) overnight and between uses to save on your energy bill.
Can you leave an inflatable hot tub out in winter?
It is not recommended to leave your hot tub outside in temperatures lower than 40°F (4°C) during the winter. The freezing temperatures can cause irreparable damage to the pump and liner. Manufacturers recommend shutting down and packing up hot tubs when the weather becomes too cold.
Packing up your spa avoids water freezing inside the pump and plumbing while you’re draining the hot tub. Follow these steps to properly shut down your inflatable hot tub:
- Cut the power: The first thing to do is turn the power off completely. After the power is off, you can unplug the heater.
- Drain: Once the jets have stopped working, drain all of the water.
- Remove the filter: Remove and give the filters and filter basket a clean with this specially formulated solution.
- Ensure no standing water: If your pump has drainage plugs, open them up and drain any remaining water. Ensure the plumbing is empty using a wet/dry vac.
Why isn’t my inflatable hot tub suitable for winter?
As we’ve seen, the lowest temperature for most inflatable hot tubs is 40°F (4°C). But why can’t they withstand freezing temperatures?
Most inflatable spas are made from a triple layer of PVC. This makes them sturdy enough to support the weight of both the water and bathers, as well as to withstand the bubbling without giving way.
Despite being tough enough even to support a fully grown adult sitting on the side, the materials still aren’t suitable for freezing temperatures.
Another issue is with the motor and heater. Most inflatable hot tubs designed for use in the summer turn the heater off whenever the jets are turned on.
With the jets on, the water is no longer flowing continuously through the motor, which means it settles in the pump and starts to cool.
In very cold weather, it won’t take long for the water inside the pump to begin to freeze and expand, causing all sorts of damage.
If it’s going to get colder than 40°F (4°C), it’s best to pack your spa away until the weather warms up again. If you like the idea of winter hot-tubbing, consider purchasing a 4-season spa suitable for soaking all year round.
4-season inflatable hot tubs for winter
Several big-name manufacturers such as Bestway, Canadian Spa, and MSpa have designed 4-season inflatable hot tubs that can be used all year round.
Inflatable hot tubs suitable for winter have as many as 6 layers, which is double the amount found in standard spas.
Top models feature a reinforced vinyl skin, thick insulated foam walls and cover, and a padded thermal base.
But the spa’s reinforced construction isn’t the only reason it can withstand the cold weather. The motors for 4-season hot tubs have been specially designed to work in sub-zero temperatures.
The pump and heater continue functioning when the jets are powered on without cutting out, meaning that the water continues to flow and stays heated.
What is the best inflatable hot tub for winter?
The number one choice is Spa-N-A-Box made by ComfortLine. It’s a cross between a traditional hard-shell hot tub and an inflatable spa and is great value for money when compared to the competition.
It has 8 wood-style panels that join together to make a free-standing octagonal shell with a capacity of 280 gallons (1060 liters) that comfortably fits 5 adults.
The model is plug-and-play and no special plumbing or wiring is needed. Its 1000-watt heater heats the water to 104°F (40°C) in 24 hours.
It has a turbo wave massage feature and 127 air jets, which trashes other hot tubs in the same price range.
The rigid panels are 2 inches (50mm) thick and are vacuum-sealed to insulate the hot tub and keep the water hot.
The spa features a thermal ground mat and an insulated lockable cover and thermal lid that ensure the water stays up to temperature overnight without having to turn on the water heater the next day.