Hot Tub High Limit Switch Location Shown and Explained

We show where a high-limit switch is typically located, its purpose, and how to deal with possible issues.
Deborah Beams
Deborah Beams
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Deborah is an incredibly talented journalist who's been working for numerous online magazines for over 8 years now. She's also our main research writer who can turn any bori read more
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Charles Eggleston
Charles Eggleston
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Last updated: September 11, 2023
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You do not want to jump into your tub only to find out that the water is extremely cold. That could be disappointing and frustrating, right? Well, the reason could be that the high limit switch has developed some fault and prevented the water from heating up. Follow closely to learn more about hot tub high limit switch location.

You may have no knowledge about the equipment as an owner. You just want to use it whenever you need it. But for information’s sake, there is a high limit switch on your spa designed to make it safe. Once the hot tub is hot and the temperature reaches high numbers, the switch deactivates the heater.

However, there could be many reasons that cause the inactivity of the temperature sensor. Hence, it is better to troubleshoot the equipment to know what could be wrong and restore the equipment.

Where Is the High-limit Switch Located on a Hot Tub?

Hot Tub High Limit Switch Location Shown and ExplainedOn the flip side, once there is a difficulty with the switch such that it does heat up water any longer, one would begin to imagine what could have gone wrong. So, you should know the location of high-limit switch of your hot tub now such that you won’t have to wait for a repairer when there is a trip to locate the temperature sensor.

There is always a limit switch at the enclosure of the heater. For most equipment, it is always located at the bottom left corner of the equipment. Oftentimes, it comes in white color and has a red button at its mid-point.

Once you expect water to heat up and it is not heating up, you first need to be sure the problem is from the heater. Once you have confirmed that the heater is the source of the problem, you should examine the limit switch of the heater. It does not matter if it is the best plug-and-play hot tubs or otherwise.

What Does It Do?

The high-limit switch helps to ensure a high safety level as you use your equipment. The high limit switch helps to break the circuit once the temperature of the water is becoming unsafe. Hence, it discontinues the reach of electricity to the tub heater.

What Can Result in the Tripping Off of the High-limit Switch?

Several factors can prevent your hot tub from becoming hot. The most common factors include;

1.     Trapped Air in the Equipment

Air could be trapped in your equipment during the process of draining and refilling. The limit switch can trip as airlocks fill the system. Trapped air in the equipment can lock your system and fill its impediments. The impediments can restrict the flow of water via the heater. Therefore, water may not get to the heater or less water may get to it.

Once the limit switch realizes this problem, it attempts to prevent the dry fire from having some damaging effect on the heater. You can fix this by removing the trapped air. Make sure the switch flips.

2.     Dirty Filter

A dirty filter is another possible reason that can prevent your heater from getting hot. Filter helps to keep dirt elements and particles away from the spa. Not cleaning it for a long time could alter the sensor switch. Clogged filters reduce circulation and do not allow water to get to the heater. A dirty filter is common with whirlpool tubs.

Once there is a reduction in the rate of circulation of the water that gets into the jet, the spa will not get enough water too. Hence, it will take in more air that could damage the heater. The limit switch tries to alter the action of air sucking.

You can remove the filter and clean it thoroughly. If there is a spare one, you can replace the previous filter. You should flip the switch once you fix it and check if it trips.

3.     Corroded Heater

Corrosion can lead to several problems such as trip breaking and limit switch malfunctioning. All these problems reduce the effectiveness of the heater. You can check the wiring, hot tub cover, heater, or other parts of the spa that can experience corrosion.

Confirm the degree of influence on the heater. If it is complete damage, you can get a new one. The replacement could be all you need to save the day.

4.     Thermostat Difficulties

You should also check the thermostat to know its state. If the thermostat is marked wrongly, you could have some challenges with the hot tub high limit switch. Check the thermostat to know if it is improperly calibrated as it could be giving a wrong temperature reading. Automatically, this can flip the limit switch.


Troubleshooting is always a valid option to explore when your limit switch does not function. Also, you can try troubleshooting to solve different problems that could arise. For example, you can troubleshoot to calibrate the thermostat properly. After that, you can check if the problem is fixed.

Troubleshooting should be the basic consideration when you are experienced with electrical systems. If you are not, it is better to seek the help of a professional. Your safety is paramount and a few dollars will achieve that for you in conjunction with time-saving.

Final Thoughts

The high limit switch of a hot tub is critical for the equipment. It is wrong to ignore such a problem no matter how little it may appear to be. Also, ignoring such an issue can cause more damages to the hot tub generally. Repairing the heater by then would make one spend more money or even replace the entire hot tub. You can always replace the high limit switch too if need be.

Hence, it is always advisable to troubleshoot your hot tub at any stance you observe some glitches or anything unusual. Always try to find out exactly the issue – it may begin with the hot tub high limit switch location. If it is beyond you, you should the assistance of an expert. More importantly, you can easily notice possible issues by carrying out regular maintenance on the hot tub.

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