Guide: What To Do When a Nest Fan Won’t Turn Off

Is your Nest fan constantly running and not turning off even when the heating and cooling is disabled?

This is a big problem as it’s unnecessarily eating up electricity and over-working your HVAC (heating, ventilation, and air conditioning).

A Nest fan won’t turn off if it’s automated to turn on at a schedule or configured to a timer. In either case, you need to disable the corresponding Nest fan settings to turn it off. Also, hardware issues can cause the Nest fan to keep spinning. In that case, you need to call a technician.

In this article, I’ll share some common reasons why your Nest fan won’t turn off.

Following that, I’ve put together a quick guide going over the Nest fan settings and how you can turn it off manually.

Why Nest Fan Is Running

By default, your Nest-connected HVAC or forced-air system will automatically turn on the fan when it’s heating or cooling.

This helps to quickly circulate the warm/cool air throughout the house, making the system more efficient.

However, most modern systems come with a separate fan wire that lets you control the fan manually.

If you connect that fan wire with the G-connector on your Nest thermostat, then it’ll allow you to automate, program, and control the fan on your HVAC or forced-air system.

Here’s a 20-min detailed YouTube video by One Hour Smart Home that offers a full explanation of the Nest wiring structure:

Now, if you choose to use the G-connector on your Nest to control the fan separately, then misconfigured settings can stop it from turning off.

Other than this, there might also be issues in the Nest wiring or the fan itself.

Let’s explore all the various reasons that are causing your fan not to stop.

Misconfigured Nest Fan Settings

Exploring the various settings in your Nest sensor is essential if you want to understand what you can do with the device.

However, when browsing through the different settings, it’s very easy to misconfigure something that’ll keep the fan running non-stop.

Here’s a look at a couple of settings that might be at fault.

The Nest Is Configured to Fan-Only Mode

There’s a setting in Nest that allows you to set a time range to turn on the fan regardless of whether you have heating/cooling enabled. 

This setting is provided to help people circulate the air throughout their homes to ensure even temperatures.

It allows you to set a range from 15 min to 12 hours.

After configuring the time interval, the fan will start and continue till the timer runs out.

Here’s a quick 1-min YouTube video by Ryan Homes showcasing how to use this option:

You’ve Set a Schedule To Turn On the Fan

Nest comes with an automation feature that allows you to set a schedule for the fan to turn on.

It also has a button that’ll enable you to activate “always” mode, in which case the fan will never stop spinning.

As you can imagine, accidentally enabling any of these features will prevent your fan from turning off.

Here’s a short 3-min YouTube video by KungFuMaintenance showcasing the “always” fan mode on Nest thermostat:

Hardware Problem With the Fan or the Nest Sensor

Hardware problems in the fan, like stuck relays or other issues with the HVAC, can cause the fan to keep spinning.

So how do you know if the problem is with the fan or the Nest thermostat?

Well, the simplest technique is to remove the Nest sensor from the wall. 

If doing so stops the fan, then the problem is with the Nest.

However, if the fan keeps spinning, then it’s likely a hardware problem with your HVAC or forced-air system.

How To Turn Off Nest Fan

By now, you should have a basic idea of how the Nest fan works and why it isn’t stopping.

With this in mind, here are step-by-step guides on how to fix those issues.

Turn Off the Fan From the Nest Settings

Is your Nest running on fan-only mode? If yes, then you can easily disable it by following the five given steps:

1. Tap the Nest Thermostat ring to open the main menu.
2. Scroll through the menu till you reach the “Fan” option.
3. Select it.
4. If the fan-only mode is active, you should see a “STOP FAN” option.
5. Select it.

The fan should stop spinning instantly.

However, don’t worry if your fan is spinning, but you don’t see the “STOP FAN” option.

It might be configured to run on a schedule, in which case you’ll have to disable that specific setting.

Disable Any Fan Schedule or the “Always” Option

To disable any activated fan schedule, follow the steps given below:

1. Tap the Nest thermostat ring to open the main menu.
2. Scroll to “Settings” and select it.
3. Scroll through the menu till you find the “Fan Schedule” option.
4. At the bottom, there’s the “DISABLE” button.
5. Select it.

If the fan was running on a schedule, this should disable it, and the fan will stop spinning.

Call in a Technician

If you troubleshoot the problem to find hardware fault in either your Nest sensor or your HVAC, you need to call a technician.

Possible damage to the Nest wiring or software problems can cause the fan to keep spinning.

In this case, the Nest support team will be able to resolve your problem.

On the other hand, if a stuck relay or issue with the furnace in your HVAC is keeping the fan running, then call your HVAC’s support team. It’s an intricate problem that requires technical expertise.

Key Takeaway

Your Nest fan won’t turn off if you’ve mistakenly automated it to keep spinning.

You could’ve either set a timer for fan-only mode or set up a fan schedule.

In either case, disabling these settings will shut down the fan.

Other than this, hardware faults in your Nest sensor, HVAC, or forced-air system can also cause your fan to keep spinning. In this case, it’s advised that you call in a technician to take care of the problem.