Signs Your Thermostat Is Bad

We recommend that you periodically test your thermostat, but you should also understand the signs that indicate your thermostat is bad so that you can perform ad hoc tests. Here are some warning signs to look out for:

• The thermostat’s display is not lit, or its buttons are unresponsive. A battery change may fix this. Otherwise, it may have malfunctioned.
• The heater or air conditioner won’t turn on. The thermostat transmits signals to activate, or deactivate, the unit. Issue with the electrical wiring can interrupt communications.
• The room temperature and thermostat setting does not match. Make sure to give the unit enough time though! If the temperatures do not match within an hour, then you might have a faulty thermostat.

How to Test the Thermostat

If you have noticed any of the aforementioned issues, then you likely have a faulty thermostat. Still, it is worth testing the thermostat.

First, let’s make sure the thermostat is responsive. Turn up the thermostat to the highest, or lowest, setting. This should activate the AC or heater. If not, then your thermostat might be unresponsive. Sometimes, simply toggling the respective circuit breaker or changing the batteries can fix an unresponsive thermostat. What about testing faulty thermostats?

Another easy test is with an indoor thermometer. Turn on your air conditioner or heater. Read the indoor thermometer then set the HVAC’s thermostat to a level different from the thermometer’s reading. Wait about an hour and read the thermometer again. The reading on the thermometer should match the setting on the thermostat. If not, then you might have a faulty thermostat.

For more technical testing, you should grab a multimeter. Turn the dial to 24 volts AC and touch one of the meter’s probes to the R terminal and the other probe to the G, W, or Y terminal. The reading on the multimeter should show something between 22 and 26 volts. If it is reading zero, then your thermostat is not getting power.

What To Do About Faulty Thermostats

Sometimes changing the battery or switching the thermostat off and on again will fix the issue. Other times, electrical and technical issues call for a repair or replacement. If you need HVAC repair or replacements, then call Rooter Hero to hire one of our AC contractors in El Cajon, CA. We are happy to schedule an appointment or arrange an emergency repair.