How Long Do Thermostats Last? (And When to Get a New One)

May 11, 2023


How long do thermostats last? Most thermostats have a 10-year lifespan before they need to be replaced. However, the exact figure depends on several factors, including:

  • Make and model
  • Year
  • Physical damage
  • Battery lifespan

The battery is a significant thermostat component, so you shouldn’t ignore it. Here, we’ll dive into thermostat-related topics, including battery concerns, the best types of thermostats, and how YES! can deliver exceptional services to ensure your device works as it should.

Table of Contents:

Thermostat FAQs

How a Thermostat Battery Works

Do thermostats have batteries? Some do. For example, battery-powered digital thermostats rely on batteries as a backup energy source. Some standalone thermostats use batteries as their primary power source. These have a power supply separate from your home’s electrical system.

The ones that use batteries as a backup source share a power supply with your HVAC, so if you experience a power outage, your thermostat will use its batteries to retain a programmed temperature setting. If the battery fails along with your home’s electrical system, the device won’t work, leaving you without functioning heating or cooling units.

Why Thermostats Can Drain Batteries

A thermostat can drain batteries if the unit is old or faulty. The temperature settings programmed into a digital wall thermostat don’t impact battery usage (if you turn down the air conditioning in the summer, it won’t save the thermostat’s battery life; it will just reduce your energy bills).

Since usage doesn’t drain the battery, the issue is likely caused by the battery type or the unit itself.

How to Check the Batteries

Locate the battery compartment on the side, back, or underneath a sliding panel with space for two or more AA or AAA batteries. Once removed, test them in another device to make sure the batteries are working and it’s not a problem with the thermostat unit’s ability to connect and draw power.

Even if the screen on a digital thermostat fades or a “replace battery” light comes on, that’s not a sure sign the battery is dead, only that the wall unit isn’t getting enough power. Non-lithium batteries may drain faster, so use a high-quality, brand-name lithium battery to ensure the longest life.

If the problem is with the wall unit, you should replace it rather than try to repair it. YES! can replace the unit with the same kind or take the opportunity to upgrade the model.

Contact us to schedule a replacement service.

Signs You Need a New Thermostat

Even if the batteries are working, a thermostat can still malfunction. Here are some signs of a bad thermostat:

  • Indoor temperatures don’t match what the thermostat shows.
  • The thermostat constantly runs.
  • The device is over 10 years old.
  • Your energy bills skyrocket.

Remember that an HVAC system depends on a thermostat to modify home temperatures. Don’t wait until the device shows signs of impending doom. Call us at 844-216-9300, and our certified YES! experts can install a new thermostat to keep you and your family comfortable indoors.

Need a New Thermostat? Why We Love the Nest Thermostat

You may decide it’s time to upgrade from a battery-powered digital thermostat that’s draining AAs at a blinding speed. If so, you should opt for a programmable or even a smart home thermostat to help minimize energy usage. YES! loves to recommend the Nest thermostat because:

  • We’re committed to 100% satisfaction for our customers.
  • You don’t need to rewire the whole house.
  • It adjusts automatically or via instructions from a Wi-Fi connection.

Visit the Nest Thermostats page for smart home thermostats.

Satisfaction Guaranteed

Whatever option you decide is best for your thermostat—replacing or upgrading to a new model—you can trust YES! to install it. We back all our services with a 100% satisfaction guarantee and offer special discounts for savings on repairs and replacements. Check out our FAQ section below to learn more about thermostats and batteries.

Contact our team today.

Thermostat FAQs

What Kind of Batteries Does a Thermostat Take?

Most thermostats use the following:

  • AA and AAA alkaline batteries
  • 9-volt battery
  • 3V disc-style lithium battery

Check the owner’s manual to determine which batteries work with your device.

What Happens When a Thermostat Battery Dies?

When the battery dies, you’ll see a black display screen, and the cooling and heating units will stop working. The result? You won’t be able to change the temperature. However, thermostats connected to your home’s electrical system will continue working despite flashing the “low battery” sign.

How Do You Know If a Thermostat Battery Is Low?

Here are some warning signs to watch out for:

  • The thermostat shows a blank touchscreen display.
  • You receive a low battery warning sign.
  • The thermostat inaccurately registers indoor temperatures.

How Do You Change Thermostat Batteries?

Although the exact method varies based on the model and brand you use, here’s the basic thermostat battery replacement process:

  1. Locate and remove the display housing from the wall-mounted plate.
  2. Pull the batteries from their slots using a screwdriver.
  3. Install new batteries into the slots.
  4. Mount the thermostat on the wall.

For a Nest thermostat, follow the same steps with two slight differences: First, pull the thermostat display off its base. Once you follow the steps above, push the thermostat display onto the base until it clicks. If you need assistance, our technicians will be happy to replace the battery for you, ensuring the thermostat works properly.

What Causes a Home Thermostat to Go Bad?

A thermostat can fail if there’s not enough power going to it. There could also be damaged electrical connections caused by loose wires. Finally, the thermostat could be dirty since dust and debris can cause its electrical components to malfunction.

Call YES! at 844-216-9300 for a thermostat repair service.

Will a Low Thermostat Battery Cause a Furnace to Malfunction?

Yes, it will. If the batteries fail, the thermostat won’t be able to signal the furnace to turn on, meaning you’ll receive zero heat inside your home. Some thermostats receive power via a 24V wire connected to a transformer inside your furnace, so your furnace will start working even if the batteries are low.

That said, since these thermostats use batteries as a secondary power supply, you’ll want to change them as soon as you see a “low battery” sign pop up.

How Do You Reset a Thermostat After Replacing the Battery?

It depends on the thermostat. For a programmable thermostat, wait five to ten seconds after installing the new batteries before turning it on. If you own a non-programmable digital thermostat, just press the reset button.

Finally, for a mechanical thermostat, turn off the circuit breaker, wait 30 seconds, then turn it back on.

Why Does Your Thermostat Say “Low Battery” with New Batteries?

The component could be experiencing glitches or bugs that cause it to display “errors” that are not occurring. The glitches could be a sign that the device is damaged.

Check for signs of physical damage around the device and the battery compartment, and give us a call. The technicians at YES! can accurately diagnose the issue and get your thermostat working the way it should.

Last Updated: March 28, 2024