How to Change a Thermostat Battery
If you see the low battery indicator on your thermostat or the display is blank, it’s probably time to replace the batteries. Although doing so may seem intimidating, it’s actually a lot easier than it seems. If you need assistance, this guide on how to change a thermostat battery explains the step-by-step process to help make maintaining your HVAC system as straightforward as possible.
Supplies
- Batteries (usually AA or AAA alkaline or 3V disc-style)
- Small Screwdriver (if needed to remove the thermostat cover)
- Flathead Screwdriver (if needed to pry out batteries)
- Camera or Cell Phone (if needed to take a photo of battery alignment)
Replace the batteries once per year, or when the thermostat display indicates that they’re low or dead. Be sure to follow all local regulations regarding the disposal of used batteries.
Directions
- Step 1. Turn the thermostat off - Flip the switch on the bottom or side of the thermostat to the “Off” position in order to minimize the risk of short circuits and system resets.
- Step 2. Determine how to remove the cover - Assess how the cover can be removed. If you notice indentations for your thumb and fingers, the cover can likely be lifted off the unit. If screws are present, you’ll need to unscrew them first. Be aware that some models have a removable battery holder in the back that can be accessed without removing the front cover.
- Step 3. Remove the outer cover/battery holder - Detach the outer cover from the mounting plate, either by simply pulling it off or loosening the screws and then removing it. If your model has a battery compartment in the back, pull it out of the unit.
- Step 4. Take a photo of the battery alignment (optional) - Note the position of the batteries in the front cover or removable holder. It may be helpful to use a camera or cell phone to take a photo of the batteries so that you know how to put in the new ones.
- Step 5. Take out the old batteries - Lift out the old batteries with your fingers. If the batteries are packed tightly, you may have to use a flathead screwdriver to pry them loose.
- Step 6. Install the new batteries - Put new batteries in the unit with the plus sign facing up, unless writing on the thermostat or directions in the user’s manual say otherwise.
- Step 7. Reinstall the front cover/battery holder - Return the front cover or battery holder to the mounting plate.
- Step 8. Test the thermostat - Check to make sure that the thermostat display screen is functioning correctly and that the unit responds when you push buttons or move switches. If desired, adjust the temperature setting on the HVAC system.