What Happens if a Thermostat’s Battery Dies?

hive thermostat low battery warning

Owning a thermostat is a major convenience. Not only does it save you the energy and time it would take to keep adjusting the temperature setting in your HVAC system, but it also saves you money. Reason being that it sets the temperature as per optimally as per your preferences thus saving energy by not overcooling or overheating your house. which in turn reduces your energy bill.

Have you ever asked yourself what happens if the thermostat battery dies? Your thermostat will stop working and this will in turn affect the performance of your heating and cooling system.

Signs That Thermostat Batteries Are Dead

In order to save yourself the trouble of having to reset your thermostat when the battery dies, you can ensure you take into account the thermostat low battery symptoms and replace them before they die.

Most thermostats have a low battery indicator that will be displayed on the LED screen that displays the temperature. The thermostat may also start beeping when the batteries are low. Alternatively, the screen may become blank making it impossible for you to adjust the thermostat. The symptoms vary depending on the thermostat brand.

Batteries are only a major problem to thermostats that don’t have a C-Wire or some means to draw power from the mains supply for instance the ecobee PEK. If your thermostat can do this and still has batteries, they will last longer as they only play backup when there is a power blackout.

Your air conditioning system may also start to malfunction as the thermostat is not able to control it efficiently. The display screen may start flashing a warning, dim out the backlight or fade out to indicate that the batteries are running low.

Does a low battery affect a thermostat’s performance?

Yes. Not only do the batteries power the LED display screen, but they also power the relay that sends a voltage signal to the circuit board for temperature adjustment services. It the batteries do not produce enough voltage, then your air conditioning system will start to act up. Because the thermostat is not able to control it.

How long do batteries last in a thermostat?

This depends on the batteries used. Some batteries may last a few months while others could last for a number of years. Most custom batteries that are provided by the thermostat’s manufacturer tend to have a longer life span.

Will a thermostat work if batteries are dead?

Some hard wired thermostats will keep working if your batteries are dead or missing as long as it has a C Wire. However, if it is designed with a battery slot, you will get constant reminders to replace or install the batteries since the thermostat uses them as a backup in case of a power failure.

If you have no C-Wire and are running your thermostat purely out of battery power, it will not function or display anything when the batteries are dead.