What Are the Signs of a Bad or Broken Thermostat?

A person's hand adjusting the temperature control panel on a wall.

Your thermostat is the control center of your heating and cooling system. It plays a crucial role in maintaining a comfortable environment. Recognizing the signs of a failing thermostat is key to resolving the problem and restoring functionality. In this guide, we’ll cover common indicators of a bad thermostat and provide solutions to solve the issue.

6 Signs of a Bad Thermostat

If your thermostat is broken, you might notice it in a few different ways. A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves. Learn more about each of these issues and how to solve them!

The AC or Furnace Won’t Come On

When you set the thermostat above or below the current room temperature, you should hear a click, and the AC or furnace should kick on almost immediately. If you make changes at the thermostat and nothing happens, that’s the first sign you have a bad thermostat.

The HVAC System Won’t Turn Off

If you’ve noticed your HVAC system running constantly, your thermostat may be miscalibrated or the wiring may have been impacted. This situation often calls for a simple repair rather than a thermostat replacement.

The Thermostat Is Unresponsive

If your thermostat display is dark or blank, even with fresh batteries and no issues with your circuit breaker, your thermostat may be broken. Another indicator is if nothing is changing on the screen when you press buttons.

The HVAC System Short-Cycles

Short-cycling is when the furnace or air conditioner runs briefly but fails to complete a full cycle. If this happens, your energy bills could increase while comfort levels go down. Several issues could be to blame for this problem, including a bad thermostat.

The Room Temperature Doesn’t Match the Thermostat Setting

If the room temperature is starkly different than the temperature the thermostat is set to, this may mean the thermostat is coming on and off when it’s not supposed to. If the system is short-cycling, this could cause the rooms furthest away from the heating and cooling systems to have the most noticeable comfort problems.

The Programmed Settings Reset Themselves

Programmable thermostats are designed to maintain their settings over the long term. If you continually find yourself having to reprogram the settings from their default state, it could mean it’s time for a new thermostat.

Noticing signs of a broken thermostat in your Northeast Ohio home? Call Blind & Sons at (330) 753-7711 for thermostat repair services!


How To Fix a Broken Thermostat

Since thermostats are easily accessible, it should be the first place you check if you have trouble with your HVAC system. To fix a broken thermostat, you should check and adjust the settings, replace the batteries, clean the thermostat, check the wire connections, and reset the circuit breaker. Learn more about each of these steps here.

Check and Adjust the Settings

First, make sure you’re not jumping to conclusions about your thermostat. Check that the settings are correct and the temperatures you have programmed are appropriate for the season.

Replace the Batteries

If you have an electronic thermostat, remove the faceplate to expose the batteries underneath, and replace them. Make this a yearly habit to help prevent problems with your thermostat.

Clean the Thermostat

If you have an older mechanical thermostat with an analog lever to control the temperature, dust can cause a malfunction. Remove the cover and gently dust the inside with a soft brush or cloth to see if that fixes the problem.

Check the Wire Connections

With the thermostat cover off, check that the wires are all firmly connected to their corresponding mounting screw. Loose wires could result in faulty functionality.

Reset the Circuit Breaker

Your thermostat might have tripped a circuit. To find out, go to the breaker box and look for the furnace or AC circuit. If the breaker switch doesn’t line up with the others, flip it all the way off, and then back on again. This should restore power to the thermostat and fix the problem. If the circuit keeps tripping, you may need to have your electrical panel serviced.

Choose Blind & Sons for Thermostat Repair

If you are still having thermostat or HVAC issues even after troubleshooting with these steps, give Blind & Sons a call at (330) 753-7711 for HVAC services in Northeast Ohio!

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