Sta Rite Pool Heater Turns On By Itself [5 Easy Fixes]

The most common reasons behind the Sta Rite pool heater turns on by itself are an automation issue, a faulty thermistor, an electrical glitch, a bad touchpad, or a malfunctioning control board.

sta rite pool heater turns on by itself

Keep reading this article to find out more about these issues in detail that causes your heater to turn on by itself and find out how you can fix them.

You’ll also learn how to turn off the power supply in these pool heaters and how to prevent this problem in the first place. Let’s dive in!

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Sta Rite Pool Heater Turns On By Itself [5 Easy Fixes]

We’ll discuss the main reasons that would cause the Sta Rite pool heaters to turn on by themselves and how you can fix them in this sta rite pool heater troubleshooting guide. Here are the five major causes of why it happens and how you can fix them:

1. Automation Issue

One of the most common reasons that cause the Pentair heater to turn on by itself is because of automation issues.

When the heater senses the temperature is lower than it should be and thinks that there’s a call for heat, it turns on.


The automation settings have to be adjusted. The way to do it will vary depending on the model of the heater you use.

Refer to your owner’s manual to learn how you can do that. If you think it’s difficult to do on your own, you can always call in a technician to do that.

2. Faulty Thermistor

When the thermistor goes bad, it reads the wrong temperature and sends it to the control board of the heater.

sta rite pool heater thermistor

That misinformation can cause the heater to turn on even when it’s not supposed to. You’d also see the E01 error code if you have a bad thermistor.


If there’s something wrong with a thermistor, you need to replace it. You can replace the thermistor in your heater by following these steps:

  • Turn off the heater and unplug it.
  • Drain the water from the heater by unscrewing the drain plugs.
  • Remove the front access panel. Take out the control box.
  • Disconnect the connector of the thermistor to the ignition control panel.
  • Pull out the thermistor. Install the new thermistor in its place.

You can put it back together as you know how to take it off by reverse-engineering the process.

Replacing it will keep your heater from turning on according to its own will as it won’t get an inaccurate reading anymore.

3. Electrical Glitch

If you’ve made sure that you have fixed the automation issue and a bad thermistor, another reason that can cause the heater to turn on by itself is an electrical glitch in your system.

That is especially the case if you don’t see any error codes flashing in the heater.

The glitch can be anywhere starting from the switch to the main panel. It’s most certainly happening because two wires that are not supposed to be connected are touching each other.

All the components and the wiring in your heater will have to be diagnosed to find out what’s causing the issue. There’s no way to tell what could be causing the trouble without looking at the heater itself.


As a temporary solution, you can turn off the breaker if the heater has an electric ignition system. For the ones that are ignited by the gas, you can shut off the gas supply to make sure that it doesn’t start.

But if you’re looking for a long-term solution, the ideal thing to do is to call in an expert technician and have him take a look at your heater.

He’ll be able to figure out what components are causing the electrical issue and how you can go about replacing them.

4. Bad Touchpad

If there are issues with the touchpad, it can also cause the heater to turn on by itself. The touchpad can age quicker and go bad when it has excess exposure to UV light. When it goes bad, it can cause problems like turning on the heater.

sta rite pool heater touchpad

Fortunately, diagnosing a faulty touchpad is easy. You need to unplug the touchpad from the control board.

There’s only one ribbon cable that’s connected to the control panel and that’s the one you need to pull out to disconnect the touchpad.

If the heater still turns on by itself after disconnecting the touchpad, that means a faulty touchpad isn’t the issue.

But if doing it keeps the heater from turning on, that means you have a faulty touchpad.


Replace the touchpad with a new one if it has become damaged. The touch pads can be priced anywhere from $30 to $250 depending on the model of your heater. But you can save on the labor cost if you do it yourself.

5. Malfunctioning Control Board

A control board that has gone bad can also cause the heater to turn on by itself.

sta rite pool heater control board

If it sends out the wrong signal to the thermistor or doesn’t communicate with it properly, it may turn the heater on by itself.


If a faulty control board is causing the heater to turn on by itself, replacing it will solve the problem.

OEM control boards are expensive and you can opt for aftermarket control boards at a much lower price. You can also replace it yourself as the control board is easy to access.

How To Turn Off Sta Rite Heater Power Supply

To make sure that your heater doesn’t turn on automatically, you can shut off the power supply to do it. You need to open the heater and unscrew a screw on the right-hand side of the heater to access a metal box.

You’ll see a red or black plug with looped wires connected to it. That plug is the internal plug that feeds power to the heater. Once you pull that plug out, the heater will no longer get power.

How To Prevent Sta Rite Heater From Turning On By Itself

These pool heaters have to be shut down correctly so that it doesn’t try to fire up on their own again. The heater will be in cooldown mode for a while after you turn it off by pressing the button on the keypad.

If you shut down the pump before the heater is done cooling, then the heater will not completely turn off. That’s why it will automatically turn itself on after a few minutes the next time you turn on the pump.

You can easily prevent this by letting the pump run for at least five minutes or more after you turn off the heater. That’ll give it plenty of time to cool down and prevent it from turning on again.


How to keep the touchpad from going bad?

There’s a cover that protects the touchpad from UV light. Make sure the cover is on the touchpad and that you don’t lose it so that you can prevent the touchpad from aging and going bad.

Why does Sta Rite pool heater cycle on and off?

The heater cycling on and off is normally caused because of electrical issues. But it can also be caused by scale build-up on the thermal regulator, heat exchanger, or a dirty cartridge filter. To fix the issue clean the cartridge filter.

Why does the Pentair mastertemp 400 turns on and off?

The most common reason that causes the Pentair mastertemp to turn on and off is a bad thermal regulator. The water can get too hot and the high limit error causes the cycling of the heater.

Is it okay to leave my pool heater on all the time?

Leaving the pool heater will increase your electricity bills, wear out the heater quicker and add more stress to the water in your pool. So, you shouldn’t leave it on and let it cycle during the day.


It’s extremely frustrating when your sta rite pool heater turns on by itself. But now you know what are the most common reasons that cause the heater to turn on and how you can fix them.

We hope this Sta Rite pool heater troubleshooting guide has helped you identify the reason that causes your heater to turn on by itself and how you can solve the problem. Leave a comment below if you have any more questions about pool heaters.

About David

David is a man who loves doing research and finding out the best solution to any type of heating appliance issues like heaters and fireplaces. Whenever he finds the perfect solutions to any issues of heating appliances after doing in-depth research, he loves to share them with his readers. In fact, his aim is to help his readers to fix the issues with their heating appliances easily.More about us .

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