How To Reset AC Thermostat When Its Not Working

The thermostat is fundamental to the overall function of your HVAC machine. Thermostats work by measuring the current temperature and then calculating how long to run the AC to cool the house down to the set temperature.

You’ll know your thermostat needs a reset if it is unresponsive or loses communication with your HVAC. Though it may sound complicated, you can easily learn how to reset air conditioner thermostat settings by following the guide below.

Thermostat for AC

Why Central AC Thermostats Could Need Resetting

Just like any other piece of technology, central AC thermostats are susceptible to issues. Sudden power outages will almost always result in the need for a reset. Electrical overloading or dirty thermostat components can also cause problems with AC thermostat functions.

When you reset your thermostat, you are restoring the system to factory settings.

It is important to know how to reset air conditioner thermostats to get the most out of your HVAC system. Learning how to reset air conditioner thermostats will ensure your home is being properly heated and cooled.

How To Reset Your Thermostat (Steps For Different Types)

Resetting your AC thermostat allows you to re-customize the temperatures to your liking. Different types of thermostats have different methods for resetting the system, but the outcome should always be a system restored back to factory settings.

Programmable Thermostat

Programmable thermostats let you adjust heating and cooling according to a set schedule. These thermostats will generally save the user money by not heating or cooling an entire space 24/7.

To reset a programmable thermostat, you should first power off the thermostat.

Next, remove the batteries from the back of the thermostat. Flip the batteries, so the positive side is inserted into the negative side of the battery terminal. Wait 5 seconds before removing the batteries and placing them back into the thermostat correctly.

Power on your programmable thermostat by holding the power button or flipping the circuit breaker back on.

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Line Voltage or Low Voltage Thermostat

Line voltage thermostats run off of direct electricity, which is usually 120 or 240 volts. These thermostats, also known as high voltage thermostats, generally accompany heating systems.

Similar to line voltage, low voltage thermostats are directly wired to the power in your home. These thermostats operate off a much lower voltage, usually 12 or 14 volts. Low voltage wiring will reduce energy consumption over time, which can save money.

To reset your line or low voltage thermostat, pop off the thermostat cover and start by cleaning all parts of the thermostat with a soft-bristled brush or compressed air.

Next, put the cover back and set your thermostat to the lowest setting. Remove the cover and repeat the cleaning process. Then, set the thermostat to the highest setting and clean again.

Fluctuating between settings and cleaning all parts of the thermostat should reset the system.

Non-Programmable Thermostat

Non-programmable thermostats work by staying at the same temperature 24/7. These thermostats, also called manual thermostats, will regulate temperatures to one set point and stay there until the thermostat is adjusted.

Since most non-programmable thermostats include batteries, an easy way to reset manual thermostats is by removing the batteries for 5-10 seconds before reinserting and powering the thermostat back on.

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How To Reset The Thermostat For Comfort & Savings

Reset Thermostat

Once your thermostat has been reset, you’ll need to re-enter your preferred settings for heating and cooling. For optimal savings and comfort, consider your settings before committing to a temperature.

  • For Winter Season
    When the temperature outside drops, you should lower your inside temperature accordingly. Most houses can be kept around 68 degrees for optimal savings in the winter. You can even turn it down lower at night when you are warm in bed.
  • For Summer Season
    When the summer comes and it’s warm outside, you should opt to keep your house around 78 degrees. This is high enough that you won’t rack up a high bill but low enough that you’ll still feel relief from the heat when coming indoors.
  • When You Have Been Away
    No matter what season it is, you can always save on your energy bill if you choose to set the thermostat back about 10-15 degrees when you are gone.

Central AC Popular Brands Thermostat Resetting

Some of the most popular central AC brands include Bryant, Honeywell, Trane , Carrier, and Lennox. Each brand offers several thermostat options.

Honeywell Thermostats

Almost all Honeywell thermostats are battery-operated, which means resetting these thermostats is quick and easy.

If you find your Honeywell thermostat is malfunctioning, switch off the thermostat and pop out the batteries from the back. Reverse the batteries, so the positive end of each battery is plugged into the negative side of the battery terminal. Wait 5-10 seconds before putting the batteries back the correct way. Once you power your thermostat back on, it should be reset and restored to factory settings.

Trane Thermostats

Similar to Honeywell, most Trane thermostats are programmable.

If you experience issues with WiFi connections or a problem with your HVAC system, the best thing to do will be to reset the thermostat. To do so, manually power the thermostat off and back on, which may involve removing the batteries briefly.

Carrier Thermostats

Carrier thermostats provide users with specific information about the features of the HVAC system, especially if anything requires maintenance. Anytime you do maintenance, you should reset your thermostat.

To reset Carrier thermostats, press and hold the “Left” button until the “Accessory Status” screen appears. Then, navigate to the accessory you want to reset. Next, press the “Right” button to select the setting. Finally, press “Left” to navigate back to the home screen.

Bryant Thermostats

Bryant thermostats require a hard reset from the circuit breaker to reset the thermostat.

Turn the thermostat off manually. Then, locate the correct circuit breaker to turn the electricity to the thermostat off. Wait 30 seconds before turning the breaker back on. Power your thermostat back on, and it should be reset.

Lennox Thermostats

Lennox thermostats are programmable and may work with an app specifically for the thermostat. Users will have access to information about issues with the thermostat, so a reset may not always be necessary.

If you have an older Lennox model, there will be a reset button located behind the thermostat’s cover. If so, remove the cover and press and hold the reset button for 30 seconds until the system powers off completely. If you have a newer model, navigate within the interface to the reset options.

Thermostat for Popular Central AC Brands

AC Thermostat Wait Message: How To Fix It

There are several reasons why you may see a “wait” message displayed on your AC thermostat screen. Generally, this means the thermostat is waiting to activate the HVAC system. It is normal for this process to take about five minutes under normal operations.

You can troubleshoot this issue by turning both the thermostat and HVAC system completely off. Wait 30 seconds before powering everything back on in the reverse order you powered them off. This gives your thermostat another chance to find the connection to the HVAC system.

People Also Ask (FAQ)

Knowing what to do with your thermostat at all times can be tricky. Check our FAQ section below to see if any of your questions have already been answered.

Where Is The Reset Button On A Thermostat?

The reset button, if included on your model thermostat, will be located on the face of the thermostat. To access the reset button, remove the cover. You may have to use a paperclip to hold the reset button down.

How Do I Fix An Unresponsive Thermostat?

If your thermostat is being unresponsive, you should reset the system, which will re-establish the connection between the HVAC system and the thermostat. Depending on the type of thermostat, you may need to locate the reset button, remove the batteries, or flip the breaker controlling that line of power.

How Do I Know If My AC Thermostat Is Bad?

Several red flags may arise if it’s time to replace your thermostat. If your energy bills are suspiciously high or if you have trouble controlling the heating and air functions of your HVAC system, it may be time to change the system.


Proper functioning of your HVAC system and AC thermostat are crucial to your comfort and health. That’s why it’s important to understand how your thermostat works and how to reset the thermostat when needed.

Knowing the ins and outs of how your AC thermostat works will help save money on energy costs and help you live a healthier life.

Josh Mitchell

Josh Mitchell

My name is Josh and I am obsessed with DIY and improving my family home. HVAC topics can be tricky for homeowners so I decided to share my knowledge on the subject. When I am not working on DIY projects, you can find me at the beach or my local coffee shop.