Hot Tub Keeps Overheating (Here’s How To Fix It…)

By James Brockbank •  Updated: 05/27/21 •  12 min read

My hot tub keeps overheating.

Hot tubs that overheat are usually due to a sensor malfunction, but an electrical problem or faulty plumbing could also cause it. Weather and prolonged use of the hot tub could also make the hot tub overheat. A simple cause of overheating is the temperature may be set too high. Try setting your hot tub temperature to 98°F and see if this helps. Removing the cover, adding cold water, and adjusting the filtration cycle of the hot tub will also help fix the issue.

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A few months ago, I accidentally set the temperature to 108 degrees Farehinite. Because it was also warm outside, the hot tub overheated, and I got an alert through my phone telling me there was something wrong.

I did some more research on the problem, and this is what I found…

If you notice your hot tub overheating, don’t panic.

There are many reasons for this and a few easy solutions.

I recommend a digital floating thermometer for your hot tub for more accurate temperature readings.

In this article,  I will go through the most common causes of an overheating hot tub and how to fix them so that you can enjoy all those long summer nights in comfort!

Let’s get started!

Hot Tub Keeps Overheating

There are many reasons for a hot tub to overheat. However, here are the most common causes and how to fix them:

The most common reasons for your hot tub overheating are:

Hot Tub Temperature Set Too High: To fix a hot tub overheating, try adjusting the temperature or turning off the breaker to see if it solves your problem.

Hot Tub Sensor Problems: Check all of the sensors to ensure they’re working correctly on both ends! If not, replace them with new ones.

Electrical Problem: If you notice that any of your electronics in or around the hot tub are not working, call an electrician immediately!

Some other problems could include:

A hot tub that overheats requires immediate attention, as overheating can cause irreparable damage.

To fix the hot tub from overheating:

Turn down your thermostat and wait for it to cool off outside before turning the heat back on.

Try adjusting ventilation if you feel excessive moisture coming out of the air jets or notice a buildup in condensation on the spa cover or around the hot tub.

Check for any defects with electrical wiring that could be causing an overload, then call a professional to repair them immediately.

If you would like to learn more about electrical setups for hot tubs, check out our article on hot tub disconnects for more information.

Hot Tub Temperature Keeps Rising

Hot tubs are susceptible to excessively hot water due to the fact that they need a lot of water for temperature regulation. In addition, the thermostat on many hot tubs can’t accurately measure higher than 104 degrees Fahrenheit which means they are not designed for hotter climates and may have problems staying at an optimum temperature outside those ranges.

Call a professional who can repair electrical wiring issues as soon as possible. You don’t want something like this happening during peak hours when you want to be using your hot tub!

Hot Tub Overheating Symptoms

Symptoms of an overheating hot tub include steam coming off the water, a hot tub heating element that stays on or continues to run even when not in use and an increase in electric usage.

You may also notice your air temperature is considerably higher than it should be during this time, especially if you’re using your hot tub at night or early morning hours as well.

For these symptoms to subside: turn down the thermostat (there might still be some wiring issues) and ventilate more often outside peak hours by removing the spa cover.

Hot Tub Temperature Too High

In general, hot tub water should be somewhere in the 98 – 104 degrees Fahrenheit range. If you’re unsure how hot it is where your tub is located, put a thermometer inside and see what it reads.

If it’s over 120 degrees F, then there might be some issues with your pump or heater that need correcting! Letting the temperature get too high can cause bacteria growth and other health concerns for those using the hot tub.

This could lead to more expensive problems if left untreated, like replacing circuit boards on heating elements.


Hot Tub Temperature Sensor Troubleshooting

Hot tub temperature sensor troubleshooting is a common fix for hot tubs that are too hot. However, if you have an older model, the sensor could be faulty and not reading correctly, or it might need calibrating if there’s been any change in weather patterns. A newer hot tub may need to replace the sensor altogether.

If the hot tub thermostat is not reading correctly and the hot tub is still too hot, it could be that there’s an electrical problem.

When this happens, you’ll need to call a professional electrician or someone who knows how to identify and fix electrical issues for repairs.

For more information on a hot tub’s average temperature, check out our article on the subject.

How to Fix a Hot Tub Overheating

If the hot tub is running on high and it’s still too warm, this means that something needs to be adjusted.

First, check your pump. Sometimes they will run continuously if there’s a problem with either the wiring or motor control board. You can unplug it from the outlet for about five minutes while you investigate other issues, then plug back in to see how things go.

Make sure all of your connections are tight as well, so nothing has come loose over time. If there doesn’t seem to be an issue with these components, contact a professional.

Check out this great article from Arctic Spas about overheating hot tubs for more troubleshooting ideas.

Some other steps on how to fix a hot tub overheating include:

Turn The Temperature Down

You may need to turn the hot tub heater down if it’s running on high. However, there is a limit to how much heat you can remove through your temperature gauge, which will be different for every hot tub model out there.

Consult with your owner’s manual or service technician.

Some people recommend turning off the power to take in more cool air before lowering temperatures.

Turning down the temperature in a hot tub will work in the long run, but it may take a few days for the water to cool down.

Hot tubs that get overheated also tend to have water care issues, check out our article on green hot tub water for more information.

Keep Your Hot Tub Cover Off

Keeping your hot tub cover off will increase air circulation and help with the cooling process. Be sure not to let leaves or other debris collect on top of it!

For the best protection against the sun in the summer I recommend the ULTCOVER Waterproof square cover to protect your hot tub.

Add Cold Water Into the Hot Tub

If the hot tub is not totally full, adding more water will help cool it down.

However, if you add too much water, your filter would have to work a lot harder than expected and could end up getting overwhelmed. This can make things worse rather than better!

Adding cold water to an overheating hot tub can help cool the hot tub faster.

Adding ice is another option, as it can quickly lower the temperature of a hot tub by about 15-20 degrees in just a few hours and will not add any extra work for your filter.

You might also consider adding an air pump with some blocks of dry ice (or liquid nitrogen) to put cold air into the spa rather than relying on natural ventilation alone!

Clean Out Dirt or Debris Causing Problems With Circulation

Before you start trying anything else, make sure there isn’t any debris clogging up the filter or blocking circulation; otherwise, all of these solutions will be ineffective or temporary at best.

Water circulation is key to a hot tub’s heat-control system. When the circulation is disrupted, it can’t effectively distribute the water that needs to be cooled.

If you know of any obstacles in your filter or if it’s been clogging up recently, clear them out and see how long before things get back on track.

Without clean filters and good circulation through jets, your heating problems will persist indefinitely!

For more information on circulation problems, check out our article on surging hot tub pumps.

Watch How Much Energy is Being Used to Heat the Water

Watch the hot tub’s energy usage to determine how much heating power is needed. If your jets are on, but you do not see a decrease in water temperature, then it may be time for an upgrade!

If there doesn’t seem to be any specific issue with circulation or filters in general, this might indicate that you need new equipment like a new heater or pump system.

If the hot tub is using too much energy, it may just be a faulty thermostat, but that could also indicate wiring or sensor malfunctions!

Check out our article on how long it takes to heat a hot tub for more information.

Call a Professional Who Knows What They’re Doing!

Call a professional hot tub technician. It’s a good idea to have them come out and make sure everything is working correctly. The energy usage will tell you if anything else needs replacing in addition to the hot tub heating system!

Hot Tub Heater Stays On All The Time

A hot tub heater that stays on all the time can be a sign of an intermittent connection, which could indicate that you need new wiring or even the controller needs replacing! This also shows that you may need to replace your thermostat as it is faulty.

A hot tub heater may stay on all the time because of weather conditions. If you notice your hot tub is always on, check the weather to see if it’s above freezing outside or below!

If there doesn’t seem to be any specific issue with circulation or filters in general, this might indicate that you need new equipment like a new heater or pump system.

If your hot tub heater isn’t working properly, check out our article on troubleshooting hot tub heaters for more information.

I recommend the Balboa Heater Tube Assembly and products like it to replace conventional hot tub heaters.

Filter Cycle Overheating

If your hot tub is overheating, it could be due to the filter cycle duration.

It’s best if you set your filter cycles to 12 hours apart and a single cycle at a time.

If the hot tub is set to filter too many hours per day, it can cause overheating.

Adjust your filter cycle duration down and set it to run early in the morning and late at night when outside temps are coolest.

Hot Tub Sun Exposure

One cause for overheating in hot tubs may come from the ambient temperature. If your hot tub is exposed to outdoor heat, it can be more challenging to reduce its internal temperatures.

To help your hot tub cool down, drain some water and add cool water to bring the temperature down.

Check out our article on using a hot tub in the summer for more information!

Consider Using a Water Care Monitor

Monitoring the health of your hot tub can often be challenging if you are not testing the water on a regular basis. This can also be a problem if you go on holiday or you are unable to take care of your hot tub due to mobility issues.

The pHin Smart Water Care Monitor for pools, hot tubs, and inflatable spas continuously tests the water and alerts you when to add chemicals with the integrated mobile app.

This water care monitor also takes constant readings of the temperature inside your hot tub. This will give you peace of mind while away from your spa.

The mobile app will inform you when to add chemicals such as chlorine, and how much chemical is recommended. This is done by entering your hot tub or pool’s unique dimensions.

Simply scan the bar code of any chemical brand and the pHin app will calculate how much chemical is to be added to the water. Most products and brands are recognized by the application.

The pHin device will sample water more than 1000 times per week to give you an accurate reading compared to using test strips.

The pHin device works with different water types including chlorine, bromine, and saltwater hot tubs, swim spas, inflatable hot tubs, and pools.

This unique device comes with a lifetime warranty to ensure your water remains clear and ready for you to use at all times.

Hot Tub Keeps Overheating: Conclusion

hot tub keeps overheating

You can fix a hot tub that is overheating by ensuring it has enough air circulation, adjusting the filter cycle duration, and running less during peak heat hours.

Finally, check for any water leaks or other damages to make sure there’s no cause beyond your control. You may need professional help if the hot tub doesn’t seem to be cooling off at all!

For more hot tub troubleshooting ideas, check out this great article from Swim University.

I hope you found this article on overheating hot tubs helpful.

Thanks for visiting

James Brockbank