Thermostat Keeps Resetting Itself? Here’s What to Try

Imagine programming your thermostat before you left for a two-week holiday. You fully expect your home to be whatever temperature you set it at when you get home.

Or you wake up in the morning boiling or freezing because the temperature is no longer at what you set it to.

There could be several reasons for a thermostat to keep resetting itself.

Or is it just restarting? While doing some research, I discovered that both scenarios are an issue, so I’ll explain and clarify the problems behind each, and provide you with several tips on addressing the issue.

So keep reading!

Is Your Thermostat Resetting, Restarting, or Randomly Changing?

Before I jump into trying to diagnose possible issues, first let’s be sure of whatever symptoms you’re facing. Then based on the terminology that fits your symptoms, I’ll explain what the issue is and let you know of any possible fixes.

Is Your Thermostat Resetting?

This would indicate that your thermostat is programable and although you’ve set temps throughout the day and week, at some point those temps reset to some other pre-defined temperature.

While this may seem to happen randomly, there should be some sort of rhythm to going on. For example, every weekday or weekend evening at 7 pm the temperature changes to X, where X is always the same thing.

If this is what’s happening, your thermostat is resetting. See below for possible causes and fixes.

Is Your Thermostat Restarting?

This should be self-explanatory but if you’re not standing in front of the thermostat and actively watching what’s going on, you could miss the fact that it turned off and then back on again. All you might know is that the previous setting is gone.

So try to determine if you thermostat is restarting before you assume it’s just reset itself. If it’s restarting, I have a list of probable causes below.

Is Your Thermostat Randomly Changing?

This could be more problematic to diagnose.

If you determine that your thermostat isn’t merely resetting, which likely indicates it’s a programming issue, then look a little deeper into some of the causes behind a thermostat restarting.

Be sure to rule out resetting issues by checking the causes and fixes for that below.

Thermostat Keeps Resetting: Probable Causes & Fixes

Most of the time someone has issues with a thermostat resetting, it’s a programmable thermostat.

1. Programmable Thermostats Resetting

According to a study done by the Lawrence Berkeley National Lab about a decade ago, 90% of American households polled said, “they rarely or never adjusted the thermostat to set a weekend or weekday program.”

thermostat setting
Check your manual for the default settings.

Here’s the thing. Even if they aren’t programmed once installed, thermostats typically default to taking the temp to the 80’s for cooling, or 60s for heating.

If there is a default, it doesn’t matter what your set your desired temp at, it will reset when the program kicks in.

Determining if the issue isn’t random will mean paying attention to the times when the temperate resets itself, so looking at the manual is the fastest step. Don’t have yours to hand? Check out our guide to finding your manual online.

Finally, if you don’t adjust your temperature for time of day or night, look to see if there is a hold setting. This can either hold the current temperature until the next time period, or permanently hold the temperature. When the thermostat is showing your desired setting, press and hold the HOLD button. You should get some sort of feedback telling you the setting has been recognized.

2. Non-programmable Thermostat Resets

This is extremely uncommon, but it can happen.

If your non-programmable thermostat is resetting or changing your set temperature, the problem may be with the batteries.

Non-programmable thermostat
Check the batteries if they need changing.

Check to see if your thermostat has a common wire—also called C wire—hooked to it. This will mean removing it from the wall. Sometimes the batteries in this type of thermostat can go bad and leak acid into the ‘stat. Replace the batteries and see if that fixes the resetting issue.

If your thermostat doesn’t have a common wire and is resetting, you should replace it.

3. Thermostat Keeps Restarting: Probable Causes & Fixes

There are several reasons why your thermostat could shut down completely or restart. Some of them will indicate a problem that means you’ll need to replace it; some are easy fixes.

Battery Issues

If you have a battery-operated thermostat the first thing you should look at for any problems is your batteries. Without the needed power, your thermostat won’t operate properly. The batteries don’t need to be dead, weak batteries are enough to mess things up.

Fix: Replace weak or dead batteries

Wiring Issues

If any wiring has come loose or become faulty, this could cause a variety of problems with your thermostat. They could be completely random.

wires with molds
Check the wiring for anything unusual

Fix: Whether you do this yourself or call an electrician or HVAC pro is going to depend on your comfort level with the task.

Carefully pull the thermostat away from the wall. If you can see any wiring that has come loose, fix it.

4. Thermostat Keeps Randomly Changing

If your issues are completely random it could be any of the problems mentioned above.

I would recommend going through all the possible causes and fixes already mentioned to see if that fixes the issue. If not, it might be time for a new thermostat.


By now, you can see there are a lot of possible reasons behind a thermostat resetting, rebooting, or just randomly changing set temperatures.

Problems can include:

  • You haven’t created a program or checked to see if there is a default program already set
  • Battery issues
  • Blown fuse
  • Loose wiring
  • It’s simply time to get a new thermostat

The good news is that you can deal with most, if not all of these problems yourself. And if you can’t find your manual, there’s a good chance you can find a copy of it online—assuming it isn’t way past its life cycle.

Thanks for reading. Hopefully you’ve found the right answer to your thermostat that keeps resetting, While you’re here, why not check out some of the related posts below?

I've been helping homeowners with appliance repair since 2016. Starting out as an enthusiastic amateur, I've since worked with many Appliance, HVAC, and DIY experts over the last 7+ years. My mission is to help fix your appliances and prevent future issues - saving you stress, time, and money. Visit my author page to learn more! Read more