Solved: Honeywell thermostat not working after battery change

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Your Honeywell thermostat not working after battery change? Try these fixes

The Honeywell room thermostat is designed to help provide cozy temperatures when you’re at home and help save energy when you’re away by controlling your HVAC system.

Occasionally, you need to change the batteries – with most Thermostat models, the battery runs out after 1 to 2 years, and will need to be replaced for the thermostat to continue working properly.

Now, cases of Honeywell thermostat not working after battery change are reported by users from time to time even when one has followed the correct procedure.

Fortunately, this is an issue you can easily resolve and have the component resume normal functioning.

Read on to learn how to troubleshoot the issue of Honeywell thermostat not working after battery change.

Honeywell thermostat not working after battery change – troubleshooting guide and helpful tips

Try these troubleshooting steps before you call a pro.

Fix 1: Check if the batteries were installed correctly

While it may sound obvious to many users, it is still possible that you did not put the new batteries in right.

For this reason, our first suggestion is you go back to the battery compartment a second time and confirm that you installed them in the required orientation.

If not, rectify the placement to ensure the correct orientation.

Quick Tip: In most cases, batteries in programmable Honeywell thermostats should be aligning in the same direction, facing up (check the markings on your battery holder if in doubt).


Fix 2: Change the batteries!

If the batteries installation is ok, it could be that your brand new batteries are not strong enough!

I know that it may appear a little simplistic but changing to a stronger batteries brand could be all you need to do.

Quick Tip: If you’re unsure about the best batteries to use for your Thermostat, purchase the same brand that came with your device- Honeywell Thermostats typically use alkaline AA/AAA batteries.


Fix 3: Reset honeywell thermostat after replacing batteries

Another troubleshooting procedure that may work is resetting the thermostat- resetting takes it back to its default factory settings and may help it clear the fault that is making it not to work.

Here is how to perform a Honeywell thermostat reset:

  1. Make sure the thermostat switch has been set to “Off.”
  2. Push the battery door open by inserting a coin (or a similar alternative) into the slot found on the door. Before this, you could attempt to see if the battery door will open by pressing it down then sliding out.
  3. Next, proceed to remove the batteries.
  4. Now re-insert the batteries but you place them backward in this instance. To be clear, the idea is to have the – pole line up with the + terminal.
  5. Let the batteries stay in this backward orientation for five or so seconds.
  6. You then take the batteries out once more.
  7. Next, re-install the batteries in the appropriate orientation. After a brief pause, your thermostat may display information (on the LED screen) meaning it’s now set for use.
  8. Replace your battery compartment lid- simply slide it back firmly.


Other fixes

Inspect the thermostat- something may have gone wrong!

Examine the thermostat because a wiring issue may have arisen by accident especially for Honeywell thermostats that need to be taken off the wall for battery replacement.

For example, you could have bumped a wire during the process leading to your thermostat refusing to work after you’re done.

Specifically, we propose that you pull it off the wall all over again for inspection.

Scrutinize the thermostat and double-check that no bare wires are touching.

Also verify that no wires are incorrectly placed or lose.

Shut the access door (on the furnace) correctly

The door switch in some furnaces engages when the access door is closed the right way making the entire system activate.

Now, if the door has not been shut correctly, the switch will not be depressed thereby cutting power to your Honeywell thermostat.

Check and shut the door as needed.

Reset the circuit breaker/replace the fuse

If your Honeywell thermostat runs off in-wall electricity, it tends to shut off then go completely blank if the fuse blows out or circuit breaker trips as a result of electrical overload.

The device will not, therefore, work even after changing the batteries until you replace the blown fuse or the circuit breaker (that supports the HVAC system) has been reset.

Open up the fuse box and install a new fuse or flip the relevant circuit breaker switch back ON and see if the thermostat will start functioning.

Replace the Thermostat

Finally, the issue may actually be due to your thermostat itself being faulty. Like any other device, your Honeywell thermostat will eventually grow old and wear out.

When this happens and you’re not aware, you’ll replace the batteries only to be frustrated since the thermostat will fail to work afterward.

In other words, perhaps it’s time to upgrade to the latest (and smarter) Honeywell thermostat.

Honeywell thermostat not working after battery change – FAQs

How do I get my Honeywell thermostat to work after changing the battery?

The easiest approach is:

First, check if you have installed the batteries the right way. If not, take the batteries out and re-insert them in the correct orientation.

Next, try to put a different set of batteries- it could be that your new replacement batteries are not strong enough.

The other simple fix you can try is resetting the thermostat as described above.

If there is still no success, check if something could have gone wrong as you changed the batteries, for example, the wiring.

The final things to check are:

  • Is the access door (on the furnace) properly shut -for some furnaces?
  • Is the fuse is blown?
  • Is the circuit breaker -that supports the HVAC system- tripped?



Well, there you go – you now know how you can fix the issue of your thermostat failing to work after changing the batteries.

Of course, if the thermostat doesn’t work after trying all the above, contact Honeywell Support Team or a certified HVAC pro if you’re out of warranty.


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