Can A Thermostat Go Bad?

With the first temperature drop of the season, your home feels like you’ve suddenly stepped into a freezer. You move the thermostat from cool to heat, and expect the furnace to turn on and heat your home. 

It doesn’t. 

So you check a few things. What could it be?

It might not be your furnace. The fault may be with your thermostat. Can a thermostat go bad? 


What causes a thermostat to go bad?

If your furnace isn’t operating, it might be your thermostat. A faulty thermostat can stop your furnace from operating during the winter, or hinder the AC during the summer. If you’re working with older technology, it may start malfunctioning. It might be faulty wiring, or a buildup of dust within the console. 

Can a Thermostat Go Bad?

If all signs are pointing to your thermostat, but you still aren’t sure, here are a few things to check?

Furnace or air conditioner refuses to turn on – before you point the finger towards your furnace, return the setting to cool and see if your AC turns on. Since a thermostat operates both heating and cooling, it’s an easy check to see if it controls one or both units, or nothing at all. If neither do and the AC was working previously, it might be something with the wiring. Contact a professional to assess the situation. 

Furnace or air conditioner refuses to turn off – a short in the system can happen at any time. If the furnace doesn’t shut off once it’s on, it could be a malfunction somewhere within the thermostat. A professional will check the wiring to ensure it isn’t frayed, and will ensure the control system is calibrated correctly.

Thermostat has no power – if a thermostat dies, you’ll often find the problem just by glancing at the thermostat panel if you have a newer model. If the digital screen doesn’t illuminate, it’s a sure sign of a bad thermostat. The best place to start is by replacing the batteries. If it still doesn’t work, you have a bigger problem. 

Is it time for a new thermostat?

If you are experiencing any of the above symptoms, it may be time for a new thermostat. Troubleshooting a thermostat is fairly easy:

Ensure the settings on the panel are correct. Make sure it’s set to “heat” in the winter and “cool” in the summer. Set the unit to “auto” instead of “on.”

Replace the batteries and check for power.

Dust a manual thermostat by removing the cover and ensuring it hasn’t built up over time. 

Adjust the temperature by a few degrees to see if you can get the unit to click on. 

If none of these troubleshooting items work, it’s time to call in a professional to further assess the problem. A heating and air conditioning expert can test the thermostat and see if it’s working. They can also help you upgrade your technology, making your heating and cooling operate more efficiently throughout the seasons.  

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