Nest Thermostat Fan Won’t Turn Off? – Here’s How to Fix

It can be very frustrating when your Nest Thermostat fan won’t turn off even after heating or cooling is disabled.

This issue is a pain in the neck as it overworks your HVAC, consumes so much electricity, and ends up piling the electricity bill.

The Nest Thermostat fan won’t turn off due if you set it on the fan-only mode or if you scheduled a specific time for the fan to turn on automatically. You can easily fix this problem by tweaking some of the settings, checking it for hardware damage, or disabling any scheduled turn on.

Now you know this issue is routine and there are a couple of ways to fix it quickly.

Let’s get deep into the details about turning off the Nest Thermostat fan and preventing the issue from occurring ever again.

Why the Nest Thermostat Fan Won’t Turn Off?

These are some of the reasons your Nest Thermostat won’t turn off fan:

1. Thermostat Malfunction

The fan could run continuously because of a faulty thermostat as it may fail to detect that it has attained the preferred temperature.

2. Poor Nest Wiring

Another reason your Nest Thermostat fan won’t turn off could be because of poor electrical wiring of the Nest or the fan itself during installation.

3. Software Bugs

A hitch in the Nest Thermostat’s system could cause the fan to keep spinning non-stop even if you disable cooling or heating.

4. Hardware Issues

The Nest could be damaged internally as a result of poor maintenance, or the courier might have dropped it during shipping.

5. Wrong Nest Fan Settings

The fan won’t turn off due to a mistake in the settings. Check if all the settings are correct and if nothing prevents the fan from running continuously.

6. It’s Set To Fan-Only Mode

The Nest has a setting where you can schedule a time range for the fan to turn on despite enabling heating or cooling.

7. You’ve Scheduled a Time For the Fan to Turn On

The Nest has an in-built feature that allows users to set a specific time for the fan to switch on automatically and you might have enabled it unknowingly.

8. Faulty Furnace

Poor installation could cause damage to the furnace or even wreck it.

Measure the AC voltage across G and C at your furnace if the fan icon doesn’t display on your Nest.

How To Fix Nest Thermostat Fan That won’t Turn Off?

Once you’ve got an idea or proof of why your Nest Thermostat fan won’t turn off, you can try out the following solutions:

Solution #1 Check the Thermostat For Hardware Damage

The easiest way to find out if hardware damage is why your Nest Thermostat fan won’t turn off is by detaching the Nest sensor from the wall.

 If removing it from the wall stops the fan from spinning, the Nest is faulty, but if the fan keeps rotating, the hardware problem could be with your forced-air system or HVAC.

Hardware malfunctions in the fan, such as faulty HVAC or stuck relays keeping the circuit closed, could cause the fan to spin continuously.

Solution #2 Reset the Nest Thermostat

If the fan won’t turn off due to a software glitch, you could reset the thermostat to factory default and confirm if it fixes the problem. 

The software glitch could be caused by bugs that corrupt the Nest’s system, making it misbehave and be unresponsive to commands.

Follow these steps to factory reset your Nest Thermostat:

1. Open Settings on the thermostat and choose Factory Reset.
2. When triggered to factory reset, confirm your choice.
3. Run the reset process.

If you accidentally changed something while exploring the countless settings in the Nest sensor or when trying to find out what else you can do with the device, the reset will also fix it.

Note: Resetting the thermostat reboots the system and wipes off all errors or accidental settings that might cause the fan to run constantly.

Solution #3 Turn Off the Fan Through the Nest App

You can also turn the fan off using the Nest App on Android or iOS to see if it could be responsive.

Here’s how you’ll do it:

1. Access the Nest App on your device.
2. Pick the thermostat you want to manage.
3. Select the fan that’s running nonstop.
4. Press Stop to turn it off.

Solution #4 Clean the Nest Thermostat

Open the thermostat and use a can of compressed air to blow away all the dust.

The fan could be malfunctioning due to dust and dirt build-up in the Nest Thermostat.

Regular cleaning of the thermostat goes a long way in ensuring dust doesn’t clatter and cause complications to the system.

Solution #5 Reconnect Any Broken Wires

After clearing out all the dust, turn off the thermostat and check for any loose or broken wires.

If you find any, reattach it once you’ve consulted the Nest’s user manual or if you’re not entirely sure of what to do, contact an expert for help.

You can also inspect the breakers, reset them if they have tripped, and check if the fan has turned off.

Solution #6 Add a C Wire

Adding a C-wire to the Nest Thermostat’s E ensures it has an enough and reliable power source and doesn’t need to cycle the fan anymore.

If you have a pulsing or your fan is constantly running, it would be best to install the C-wire regardless of what the setup process recommends.

Tip: A C-wire (Common wire) connects a WiFi thermostat to a heating or cooling system (furnace) thereby providing continuous power.

Solution #7 Tweak the Nest Settings

If you’ve discovered that your Nest Thermostat is running on the fan-only mode, you can disable it by following these simple steps:

1. Gently press the Nest Thermostat ring to display the Menu.
2. Navigate the menu and find the Fan option, then choose it.
3. Click on the Stop Fan option to deactivate the fan-only mode.

Tip: If you don’t see the Stop Fan option yet, the fan is still spinning, it might be running on a set schedule, and for that reason, you’ll deactivate that setting to restore normalcy.

Solution #8 Disable Any Scheduled Turn On

If the issue is a scheduled turn on, here are the simple steps to disable the setting:

1. Open the Menu tab by pressing the Nest thermostat ring.
2. Navigate to Settings and click on it.
3. On the Settings tab, find the Fan Schedule option and select it.
4. Click on Always then select Disable to deactivate it.

Quick Recap:

Poor electrical wiring, thermostat malfunction, or wrong Nest fan settings could cause your Nest Thermostat fan to spin continuously. Now, don’t get all worked up over this issue. Turning off the fan from the Nest App, resetting the thermostat, or disabling any scheduled turn-on can effectively resolve the problem.

Read Next: Why Does Nest Thermostat Keeps Going into Eco Mode?

Bottom Line

Now we hope you have learned some of the common reasons the Nest Thermostat fan won’t turn off and the different troubleshooting techniques for the issue.

Let us try putting this knowledge to practice and fix this nuisance once and for all.