“Is your nest thermostat not cooling? Is it not allowing you to set the temperature? So, this article is for you that discuss all the possible troubleshooting guide.”

Nest thermostat is an excellent smart device for home or business owners. The device’s technology works to regulate the room temperature remotely.

It saves time, effort and is more effective than traditional AC remotes. 

Sometimes users complain their nest thermostat is not cooling or, the device does not turn on AC.

Honestly, users found a handful of reasons while their nest thermostat stopped cooling. 

However, developers say it is because of the poor wiring in the device’s backend.

Therefore the wiring should be well-organized in both thermostat and AC devices.

Still, there are possibilities for multiple reasons Why Nest thermostat is not cooling or reaching the set temperature.

Also read: Why is your nest thermostat blinking red?

Why My Nest Thermostat Not Cooling to Set temperature?

Nest thermostat not cooling to set temperature

As mentioned, a poor wiring setup can make the nest thermostat stop cooling.

Sometimes, users labeled wires at the conventional side of the thermostat. In contrast, professionals advised conducting this setup on the “heat pump” side.

Indeed, this is the first reason why the Nest integrated ac doesn’t blow cold air.

  • Maybe your thermostat is not cooling due to a power outage.
  • Perhaps your nest device is not compatible with AC integration.
  • Due to regular use, nest thermostat may experience a technical fault, restart before starting.
  • Wrong wire installation in your AC. Maybe there is a lack of connection in the Y1 terminal.
  • For longer use nest thermostat batteries may go low.
  • Motion sensors in the thermostat may not work properly.
  • Your smart device may disconnect Wifi automatically after a while.
  • Internal damage in your Nest may cause frequent noises like clicking or thumping.

So above are some common issues with nest thermostats.

Below we discuss how to fix those issues that create trouble in the devices.

How To Fix If Nest Thermostat Not Cooling?

Missing or incomplete connection is the main reason behind the troubles in the Nest thermostat.

Besides, multiple factors vary why your device does not work for cooling. So checkout below to fix those problems quickly.

#1 Confirm your cooling system

Many owners make mistakes in identifying their cooling system type.

Suppose you have a heat pump system but you set up the wires in (old thermostat) conventional rows.

So it is essential to confirm the type of cooling system you have.

For that, you can check the backend of your home device. Those sections include the product label, class, and manufacturing details.

Suppose you are still confused about the type of your cooling system.

Google with the model number and search for detailed information. After the confirmation, relabel the wires according to the compatible setup.

You can take help from the free Nest thermostat compatibility checker.

#2 Check nest thermostat wiring

This is the first thing you should check if the AC doesn’t cool.

Sometimes, the Nest thermostat contains bulk or loose wiring connections underneath.

This can cause damage to your device besides being unable to cool. So make sure the internal wiring is well organized in the Nest.

  • First, disconnect your device and make sure there is no power supply. It will save you from getting damaged while wiring.
  • Now take the display screen from Nest and check the connection.
  • Ensure that the wires are in the right place and doesn’t lose any connection.
  • After That, replace the screen and turn on the power supply.
  • Wait for a minute and start the device to check.

#3 Disconnect Common wire

Now common ( C ) wire allows 24 VAC power to flow continuously to the thermostat.

Now this “C” wire comes connected to the Nest.

However, some users claim disconnecting this standard wire opens all the options.

It also helps the Nest to reach the target temperature.

So you can also try this trick if the Nest thermostat is not cooling.

Now follow the below steps to perform the task

  • Turn off the power supply in your Nest.
  • Open the wiring chamber in the device.
  • You see already connected wires like Y1, W1, C (common) and RH-power.
  • Now disconnect the “C” wire and leave the device for a while.
  • Turn on the power and re-check the thermostat.

#4 Take a look on circuit breaker box

Still, your Nest thermostat not cooling?

Check the circuit breaker box if there is any tripped breaker. “Turn off” switch in your circuit box can stop the device from working correctly.

So turn on the switch (make sure all buttons are on) and wait for the breaker to reset.

#5 Auto schedule may unable

Nest not cooling at night or “nest” AC not blowing cold air when required?

Maybe the auto-schedule is enabled. You need to know that the Nest thermostat includes an Eco-friendly feature to control the temperature remotely.

Many Users enabled this feature and forgot.

As a result, the device cools as it preset and occurs with lack of temperature sometimes.

In this case, you need to disable two options in your Nest thermostat.

  • Open your nest application through mobile.
  • Find the ECO-temperature option and disable it.
  • Go to the Auto-Schedule option and disable.

#6 Functions of RC / RH wiring

New nest thermostat devices include separate RC and RH wires to connect. In contrast, some users run old thermostat devices.

Those regulating components form a single “R” wire with a piece of metal.

It is the only connection to the bridge with RC and RH port. If so, connect this single wire to Nest’s RH port.

Then start the device to check. If the device is still unable to work, reconnect the wire to the RC port in Nest.

#7 Maybe A blown fuse cause Issue

Blowing a fuse in the air handler can also cause the “nest thermostat” won’t cool.

Now you should check the inside of the handler if there is such difficulty.

You need a removal tool like a screwdriver to open the cover. After opening, you see a small circuit with a couple of fuses attached.

If you find the blown one, great! if not, then replace all the fuse.

#8 In-compatible Nest

Indeed, the Nest thermostat is not compatible with all devices.

There are few systems available that may not work with this google device.

Few systems that are compatible with Nest are

  • Millivolt heaters like a wall or floor heaters
  • High voltage systems etc

Check out the Google support page to know the list of incompatible devices with Nest.

#9 Keep Nest Software Updated

This is the least possible reason why the Nest thermostat stopped cooling or not functioning.

Keeping the software updated is essential.

Many users see a sudden disconnect from Wifi to the device. It happens due to outdated software.

So go to the application and click on the update tab. See if there is an option to upgrade. 

#10 Check Y1 Terminal Connections

In your Nest thermostat, certain connections are found. The followings are 

  • Y1 wire for cooling
  • W1 for heat
  • C is a common wire  
  • RH-power

Some experts say that removing and inserting the Y1 cable will help resolve the cooling issue.

So you can apply this trick also after checking the above steps.

How To Factory Reset The Nest Thermostat?

After performing every possible reason if the Nest thermostat is not cooling, you should conduct a factory reset.

Maybe a complete refresh will resolve the problem within a minute. So follow the steps below to factory reset.

  1. Open the application (NEST) on your smartphone.
  2. At your home screen, located on top left corner.
  3. Select home (if connected to multiple houses) that has the thermostat you want to delete.
  4. Tap on the thermostat you want to remove from the app screen.
  5. Now go to “Setting”, located on the upper right section.
  6. Scroll down at the bottom.
  7. You get a option that asks “confirm thermostat” in red color.
  8. Tap to confirm, and your thermostat will be removed from your Nest account.

How To Force Nest Thermostat to Hold Temperature?

Now, if you want to adjust or preset the temperature in the Nest thermostat, follow the steps below

  • Open the NEST application on your smartphone
  • Go to the top left corner and tap the dots
  • Select your thermostat ( ensure that the device is in its heat and cooling mood )
  • Tap on the hold temperature
  • Hold it until your set the count in your thermostat


So above are the reasons and solutions for why Nest thermostat is not cooling.

Keep in mind, losing connection is the main reason behind the issue.

Besides, several minor mistakes can also occur with challenges in the Nest thermostat. So without any worries, revise our guide and follow the steps to identify and resolve your issue.


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