Low thermostat batteries can cause your thermostat to have a blank screen and or malfunction. If either of these things are occuring we would recommend you check your batteries before calling a service company out. Checking your thermostat batteries before you call a service company could prevent a costly diagnostic.
However, it’s important to know that some thermostats have batteries and some do not.
To check if your thermostat uses batteries, you’ll need to open or remove the cover of your thermostat. Once the cover is opened or removed, it will be visibly evident whether or not batteries are required. If you find that your thermostat requires batteries, try a fresh pair to see if the thermostat performance improves. In the case where new batteries don’t fix the problem or where the thermostat doesn’t use batteries, it’s best to contact a service professional to resolve your problem.