Hot Tub Won’t Heat Past 95 Degrees- Troubleshooting Guide

Nothing exceeds the experience of a relaxing hot tub bath on a chilly winter evening but nothing can be more irritating than a stubborn tub, refusing to warm up. Such a tub will leave only two residues; an angry owner and a less than satisfactory experience.

However, before you go kicking the tub in rage, hoping your fury might heat it instead, there can be several reasons, which may potentially be having to do something with the problem.

You might need some troubleshooting and diagnosing, however, to find out why your hot tub won’t heat up.

Why Won’t It Heat Up?

Although there can be several reasons, here we delve into some of them-

1. Electrical Element Problems:

An electrical element is what heats the moving water in your pool by gradually raising the temperature. If it goes bad, your tub will not heat up past 95 degrees. It might not even reach 95 at all. There are three scenarios in this case:

  • Mineralization of Heating Element: 

It usually happens over a longer period, more so by using hard water. The minerals (Ca and Na salts) are deposited, forming an insulating layer, thus reducing heat transfer. It can be fixed by submersing the heating element in vinegar water or any anti-clog substance.

You can get a heating element replacement here.

  • Cracked Heating Element

It happens abruptly when your heating element is cracked internally, which will disrupt the proper flow of electricity. Your tub will still heat up but not past 90-95 degrees. To troubleshoot this, you need to get your element replaced or repaired by a professional preferably.

You can get a heating element replacement here.

  • Outer Coating Cracks

Similar to the previous one, this can take place abruptly. If the outer coating of your element gets cracked, the electricity passes into the water, which will cause the heater to trip, leading to less heat generation. The only permanent solution to this is to repair your heater as a whole.

2. Control Panel Issues:

Control panel issues are not uncommon and can arise if someone has messed with it, if you’ve had a power failure, or someone changed the programming intentionally. Here are a few control panel errors you can see if it isn’t heating as per your need:

  • Dry

It appears when the water entering the heater is insufficient to be adequately heated. The reason for the occurrence might be any blocked or clogged hose.


These errors arise when sensors are not working properly or have a circuit problem. If this occurs, it could be dangerous to use your tub, as there could be electricity in the water. To fix this, it is better to call a technician.

  • Flow

As the name suggests, it appears due to improper flow. It may appear due to any blockage, leakage if your pump is not working correctly or if your jets are malfunctioning.

3. Bad Thermostat or Temperature Sensors: 

Most new hot tubs use a thermostat that has a temperature sensor connected to it. It can shut the heater off when set temperatures have been reached. A bad thermostat or temperature sensor can also lead to your tub not heating past 95 degrees.

It happens when one of either misreads the temperature and cuts off the power to the heater. There are different ways to check if your thermostat is working properly:

  1. If you have one of those thermostats with a knob, you can turn it to check if it’s broken or not. You should also check the sensor bulb. It could be rusted if not used for longer periods, signifying that your thermostat is broken. You can get a replacement here.
  2. If you have a thermostat with a pointer, you need to check if it is moving with the changes in temperatures. Also, check the wires if they are plugged in.

4. Hot Tub Cover Issues:

Hot tub cover issues can include any breaks or cracks in the cover layer. It may be damaged, torn, or it could have a mineral deposition. All of these situations would require timely replacement. Any openings will allow heat to escape, and your tub won’t heat up.

Hot tub cover by Classic Accessories would be an excellent choice for replacement.

5. Wiring Issues: 

If your tub has been out of commission for a long time, maybe during the summers, rodents and pests might make it their personal space, thus chewing and feasting on your wires. Any frayed wire will not be electrically accurate and as a result, not heat your pool correctly.

Another issue that arises with wires is if they melted. The scorching heat of the sun can melt away the wires’ insulation. An uninsulated wire is prone to short circuits and mishaps.

It is always best to get a checkup done if you’re using your tub after a long time or, in this case, if you feel it is not heating up properly.

6. Wrongly Set Temperature 

Last but not least, your tub and its wiring, cover layer or any equipment might not be at fault at all. It may just be a human error. Maybe a member of your household set it at that temperature, therefore, before going into any technicalities, it is always better to go through your control panel.

Some Other Common Issues: 

We have mentioned some of the most common reasons why your hot tub might not be heating past 95 degrees. Here are a few rare ones:

  1. Your filter could be dirty.
  2. Your hot tub hasn’t been running long enough.
  3. You have added an air blower.
  4. You have a faulty Ground Fault Circuit Interrupter (GFCI).

Check out our comparison of two of the hottest hot tub brands at the time, Hot Springs Vs Sundance.

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