Procedure for Replacing Thermostat Battery

A dead thermostat can leave homeowners without control over their HVAC system, leading to discomfort and high energy bills until batteries are replaced; it's advisable to keep spare batteries on hand and know their location for emergencies.

While older thermostats ran on mercury, the latest models are powered by their HVAC system and rely on replaceable batteries to function. In most cases, these batteries will need to be changed annually. Unfortunately, many models differ, so detecting and replacing a low battery can be tricky.

Here are some pointers to help homeowners get started:

Know the signs

All thermostats report a low battery differently. The panel may have its specific way of alerting homeowners that a change is forthcoming. Some signs include:

• A flashing LED close to a battery icon on the thermostat panel

• A flashing battery icon on the display

• The entire display appears dimmed or faint

• Any inputted commands are slow to register or unresponsive

• Any tones the thermostat makes sound slower and weaker

Replacing the batteries

Before replacing the batteries, please check the thermostat manual (or find it online) to learn how to do it. Alternatively, start by carefully trying to detach the panel from the wall.

Thermostats can be detached in different ways:

• Some top panels are screwed in.

• Others can detach with a simple snap.

• Some panels slide off vertically or horizontally.

• Others have a battery slot that can detach from the unit.

Try to be as careful as possible in all cases, and don’t force the thermostat too much.

When replacing the batteries, examine the size and type, e.g., lithium, alkaline, etc. Most thermostats use AA, AAA, 9V, or 3V button batteries. Note that some panels may have a small button battery that cannot be detached. For that reason, be sure to exercise caution.

Keep extra batteries

A dead thermostat means homeowners have no control over the entire HVAC system. Until the batteries are replaced, this may result in an uncomfortable temperature in the home and high energy bills. Know where the batteries are beforehand and keep some in stock in an emergency.

Persistent problems

If a thermostat panel isn’t restored after replacing the batteries, then it may be a sign of other problems:

• Corroded battery contacts that will need replacement.

• The overall age of the system can cause problems.

• Incorrect voltage causes power fluctuations and surges, which could damage the thermostat or render it ineffective.

Play it safe and contact the professionals

Failed DIY work on an HVAC’s electrical components can be dangerous and costly. If the above issues arise, homeowners must contact a professional HVAC service to examine the problem and conduct the necessary repairs.

When you need heating or refrigeration service, maintenance, or repair, call us at Affordable Comfort A/C and Heating at 602-574-1205.