How And When To Change Thermostat Batteries

If your heating and cooling just isn’t turning on, a good place to start troubleshooting is with the batteries. Batteries are important for the thermostat, especially newer “smart” models, because when they go out, the thermostat might not be able to gauge what the temperature is, so it can’t send signals to the HVAC system. This prevents it from kicking the system into gear when your home gets either too hot or too cold 

Batteries are even necessary for thermostats hooked up to the electrical because they help to keep thermostat settings in place when the power goes out. When the settings are lost in an outage, the thermostat will probably need to be reprogrammed. So how do you know when the thermostat batteries need changing?

How Do I Know If My Batteries Are Low Or Dead?

The most obvious sign that you need to change your thermostat batteries is when the thermostat literally tells you the batteries are about to die! Most programmable models will now flash a low battery warning, usually about a month or two before the battery completely dies. It might be a flashing light, a battery symbol, or words spelling out the warning; whatever it is, don’t ignore it. 

The warning comes on so early because, well, humans procrastinate. Your thermostat is giving you enough time to buy new batteries before they die. When the screen on your programmable thermostat is completely blank, you’ll know the batteries are completely out of juice, and it could come at a bad time. 

Properly Changing The Batteries

When changing the battery, consult the owner’s manual for your model of thermostat. Opening the thermostat can vary by manufacturer and model, and you’ll either have to remove a battery compartment or slide the thermostat off the plate holding it to the wall to reveal the spot where the batteries are held. 

Even today, there isn’t a common standard among manufacturers for a type of battery used, and thermostats may take AA, AAA, or 3V lithium batteries. Check your manual for the proper batteries, and if it needs lithium, make sure to carefully read and note the size. It’s always good to have backups on hand, The batteries should be changed around once a year, though it’s good to get into the habit of putting fresh ones at the beginning of either the air conditioning or the heating season.

If you have to leave the home for more than a month, a proper act of precaution is to change the batteries just before you leave. If the thermostat is in a vacation home or cottage, make changing the batteries one of your chores when opening it up for the season. 

One final note: make sure to put fresh batteries in! Don’t put old-looking, rusty ones you find lying about – they could leak and corrode, ruining the entire thermostat. Contact us to learn more!