What to Do When Your Thermostat Isn’t Working

Your thermostat is the command center that tells your air conditioner when to turn on, when to turn off, and how long to run in between. When it’s not working, you won’t get the cool air your home needs. Here are some troubleshooting steps you can use to get to the bottom of a broken thermostat.

Check the settings

First things first, make sure your thermostat is turned on and to the correct settings. It sounds simple, but sometimes professionals get called out to fix a broken thermostat that’s just turned off. Double check that the switch is in the on position and that it’s set to cool instead of heat.

Replace the batteries

If your thermostat isn’t responding, the solution may be as simple as replacing the batteries. Some thermostats are wired to a home’s electrical system, but many use batteries. Battery-powered thermostats typically display a low battery warning at least a month before the battery goes dead completely, but this can be easily overlooked.

To locate the batteries in your thermostat, take off its cover. The back panel of the cover should tell you where the batteries are located and give you instructions for replacing them. If not, consult your thermostat’s manual.

Check for loose wires and screws

While you’re looking at the inside of your thermostat, check and see if you can visually identify any loose screws or wires. If so, tighten them as needed. It’s important to make sure the power to your thermostat is turned off completely before attempting to tighten any components. If you don’t feel safe doing so, an HVAC professional can help.

Clean the thermostat

Dust, dirt, and other debris can disturb the components inside your thermostat. To clean your thermostat, start by removing the cover to access the inside. Then, gently dust and wipe away contaminants with a soft dry cloth. For tough-to-reach spots, use a can of compressed air. Once everything looks clean, put the cover back on and see if your thermostat will power on.

If your home is older, you might have a mechanical thermostat as opposed to a newer digital one. Mechanical thermostats use a lever to adjust the temperature setting by hand, rather than by setting the input on a digital screen. They’re also prone to malfunctioning when they get too dusty. To fix this, clean the thermostat by removing the cover and carefully dusting inside with a small brush.

Replace the thermostat

If all else fails, it may be time to replace your thermostat. Depending on the model you choose, you can save energy and money with the modern efficiency settings. According to the EPA, homeowners can save around $180 a year by using a programmable thermostat and setting it to raise/lower temperature depending on the time of day. For ultimate control, consider upgrading to a Wi-Fi enabled smart thermostat. Smart thermostats like Nest are able to “learn” from your usage patterns over time and will eventually adjust the temperature to your daily habits and the changing seasons.


Reset the thermostat

A tripped circuit breaker could be the cause behind your unresponsive thermostat. Power outages and surges can overwhelm your air conditioner’s circuit, causing it to trip. You’ll need to locate your home’s circuit breaker box to confirm if this is happening in your home. The exact location differs, but you can typically find a circuit breaker box in the garage, a closet, the laundry room, or on the exterior of your home.

To reset the circuit breaker, look inside the breaker box and find the one labeled air conditioner or HVAC. If it’s been turned from on to a neutral position, reset the circuit by turning it off and then back on. Make sure to wait 30 minutes before trying to turn your thermostat on, to avoid tripping the circuit breaker again.

If the breaker trips again, a larger electrical problem may be present. For your safety, don’t turn it back on. A tripped breaker is your home’s way of protecting your appliances and electrical equipment when voltage is too high. Depending on the cause, you may need to work with an electrician or HVAC professional to get your thermostat and AC system back to powering on correctly. Common causes include:

  • Refrigerant leaks
  • Dirty air filters
  • Compressor problems
  • Lack of maintenance leading to electrical issues

How to keep your home cool with a broken thermostat

While troubleshooting your broken thermostat, your home may start to get uncomfortably warm. In the summer, going without air conditioning for a long period of time constitutes an HVAC emergency. Thankfully, there are tips you can use to cool down while you fix the problem or wait for a professional to arrive.

Turn on the fans

Ceiling fans, desk fans, and oscillating floor fans are great tools for keeping your home cool without air conditioning. While fans don’t actually reduce the temperature in a room, the increased movement of air is able to trick your body into thinking the temperature is lower. To take your cooling to the next level, fill a large bowl or baking sheet with ice and position it in front of a fan. The fan will blow air over the ice and create an extra-chilled breeze that’s sure to cool you down.

Close the blinds

It’s estimated that up to 30% of unwanted heat in your home comes from your windows. Shades, curtains, and blinds can lower indoor temperatures by up to 20 degrees. Because of this, keeping your home as dark as possible is a crucial step in keeping cool without air conditioning. To keep the sweltering sun at bay, close the blinds, shades, or curtains on every window in your home. If any of your windows lack blinds or other coverings, you can use bedsheets or blankets secured with duct tape or thumbtacks as a temporary DIY solution. It may not look nice, but it’s effective in a pinch.

Turn off and unplug

All lightbulbs give off heat, which can contribute to the overall temperature of your home. Keeping all but the most necessary lights turned off can reduce the impact of this heat source. Large electronics such as desktop computers or gaming consoles can also make your home feel warmer when they’re turned on. It’s best to turn off and unplug these devices when you’re not using them.

Trust Chas Roberts for thermostat solutions and more

From fixing a broken thermostat to installing a whole new system, there’s no HVAC problem too big (or too small) for our experts to take on. Contact us for all your HVAC needs.