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Nest Thermostat Heating Instead Of Cooling & How To Fix It?

We all want to make our house feel comfortable. So, most homes are equipped with modern technology, which is beyond security and gaming systems. A smart house mostly includes a nest thermostat for easy control. However, you might need to check if you are facing an issue with your Nest thermostat as it is not cooling.

The Nest thermostat is a device that can be set for businesses and homes. The technology included in this device is very effective and can regulate room temperature through remote control. It is a great way to save effort and time and is said to be more effective than the conventional AC remote.

However, many times it has been reported by users that the Nest thermostat device is not working properly. It is unable to switch on the AC. There can be several reasons why the thermostat has stopped performing. However, most of the technical people would say that poor wiring is one of the prime reasons why the Nest thermostat is not cooling correctly.

So, it is a must for you to take care of the wiring system of the Nest thermostat and make sure that it is well organized both for AC devices and the thermostat. However, there will still be some possibilities of your “Nest thermostat not cooling” issue. So, in this guide, we will find out some details about the causes and the possible fixes for the Nest thermostat not cooling issue.

Why Is My Nest Thermostat Not Properly Cooling To The Set Temperature?

As discussed above, the wiring system is one of the prime reasons why the Nest thermostat might have stopped cooling. There are many times when users have labeled that putting wires on the conventional side of the thermostat might be a reason. Most professionals will advise you to conduct the setup on the heat pump side.

No denying that this can be one of the prime reasons why your nest thermostat is not cooling. However, let us check out some of the other reasons why it might show issues.

  • One of the other reasons why your Nest thermostat is not cooling properly is due to some power outage. So, it is initially recommended to check the power connection properly flowing to the device.
  • The nest thermostat device might not be compatible with the AC. It is, again, a must for you to check the compatibility before you choose to integrate it into your home air conditioning system.
  • When you are using it regularly, there are chances that the nest thermostat might have some technical issues. So, it is better if you restart the device before you start using it.
  • You might be making the wrong installation for your AC, especially the wiring. You have to make sure that there is a proper connection with the Y1 terminal.
  • When you keep using the nest thermostat for a longer time, there are always some possibilities that the thermostat batteries might have gotten slower.
  • There might be some internal damage in the nest thermostat, which is causing frequent noises like thumping and clicking.
  • You need to check the smart device as there are always some chances it automatically gets disconnected after a while. So make sure that both the Wi-Fi connection and the smart device are thoroughly connected.

So, these are some of the most common reasons why you might face the issue with the nest thermostat not cooling. However, don’t get worried, as, in the next section, we will talk about some of the most possible and easiest fixes that can resolve the issue.

How Can You Fix The Nest Thermostat Not Cooling Issue?

So, now that you have known some of the most common reasons why you face the “Nest thermostat not cooling issue,” it is time for you to look for possible remedies. An incomplete or missing connection is always one of the reasons that you face trouble with the Nest thermostat.

Apart from this, there are several other factors that can result in the nest thermostat not cooling issue. We have already talked about the reasons in the above section, and now we will check the possible fix that you can choose to resolve the issue.

1. Confirm The Type Of Cooling System

There are many owners who mostly make a common mistake while identifying the cooling system with the type. In case you are using a heat pump, and you would like to set the wires on the conventional rows, it is a must for you to understand the kind of cooling system you already have.

You can easily do this by checking the home device’s backend. These are the sections that include product class, level, and other manufacturing details. This will provide you with complete information about that system and if it is compatible with the device.

However, if you’re still not getting the confirmation, it is better that you Google the cooling system type by searching the model number to get complete information. Make sure you set up the wire according to the cooling system type.

2. Check The Nest Thermostat Wiring

The first thing that you must check is the nest thermostat wiring if the AC does not cool. If you know the setup, you must know that the nest thermostat contains loose or bulk wiring underneath. This sometimes can result in improper functioning of the nest thermostat.

Apart from making the device incapable of cooling, it can also damage it. So, it is always a must for you to check the internal wiring and the way it is organized in the Nest.

  • Try disconnecting the device by making sure of no power supply. This is a mandatory step as it protects the device from getting damaged while setting up the wiring.
  • Now have a look at the display screen of the Nest and look for the connection.
  • You now need to make sure that all the wires are correctly placed and that there is no loose connection.
  • Once you’re done, you can choose to replace the screen and then switch on the main power supply.
  • Wait for a few minutes and then again start the device.

Check if it has resolved the issue that you are facing. If not, try the next fix.

3. Disconnect The Common Wires

Every thermostat comes with a common wire which has the capability of allowing 24VAC power to flow to the thermostat continuously. This wire is denoted as C and remains connected with the Nest.

There are many users who have claimed that disconnecting the common wire opens a lot of options. It is also possible for the nest thermostat to easily reach the target temperature. So, it is better to start trying that trick in case the nest thermostat is not properly cooling.

Following are the steps that you need to perform to disconnect common wire.

  • Switch off the nest power supply.
  • Carefully open the device’s wiring chamber.
  • When you open it, you will find the connected wires like C, W1, Y1, and the RH power.
  • It is now time for you to disconnect the Common wire and then let the device sit for a while.
  • Once you have properly done this, it is now time to switch on and check if the thermostat is working properly.

4. Check The Circuit Breaker Box Thoroughly

Is the nest thermostat still not cooling properly? If not, it is time for you to have a look at the circuit breaker box. This will help you to check if there are any tripped breakers. Remember that switching off the circuit box will result in stopping the entire device from working.

So, you must switch on the buttons and then wait to reset. It can sometimes be difficult for people with no technical knowledge. So, you need to be very careful with it and make sure that you’re not making any wrong moves with the circuit breaker box.

5. Auto Schedule Might Be Unable

Are you facing the issue with your nest thermostat as it is not cooling at night, or it might not be blowing cold air when you need it? If this is the issue, this specific solution might be a beneficial choice.

You must check the auto schedule to make sure it is enabled. Remember that the Nest thermostat is a smart device that comes with an eco-friendly feature. Therefore, it will try to control the temperature remotely. There are many users who enable the auto-schedule feature and then forget about it.

This can result in the device cooling at the preset temperature, and you are not able to get what you need. In such a case, you definitely require disabling the options in the nest thermostat.

  • Use your mobile to open the nest application.
  • Look for an eco-temperature option and make sure to disable it.
  • Visit the auto-schedule option and then disable it.

6. Check The RC / RH Wiring Functions

If you’re using the latest nest thermostat devices, you must know that it includes different RH and RC wires. On the contrary, even there are some users who are still using old thermostat devices. All the components are regulated from a single R wire made of metal.

This is probably the only connection that works as a bridge between RH and RC ports. So, it might help if you try connecting this R wire to the RH port of the nest thermostat.

After making the alteration, you might need to start the device once again. Try reconnecting the RC port of the Nest to the wire if it is still not working perfectly.

7. A Blown Fuse Might Be Causing The Issue

If there is a blown fuse in the air handler, it can also sometimes result in facing the nest thermostat not cooling issue. So, for this, you must check inside the handler and make sure there is such an issue.

Performing a check will require a compatible removal tool for successfully unscrewing the cover. Make sure that you have a screwdriver. Once you open the cover, you will find a tiny circuit with a number of fuses attached to it. In case you find any blown fuse, you have just found the leading cause. It is time for you to get rid of it.

However, if there is no blown fuse, it is commonly advisable to change all the other fuses.

8. In-compatible Nest Device

There are always some chances that the net thermostat is not properly compatible with all the other devices. So, you might need to do complete research on the systems available in the market that might not work with your device.

Following are the systems that are not compatible with the nest device.

  • High-voltage systems
  • Millivolt heaters like a floor or wall heater

You can also check the support page of Nest on Google to find out the list of devices that are incompatible with this innovative device.

9. Make Sure Of An Updated Nest Software

It is one of the most common reasons you will find the “nest thermostat not cooling” issue. It can also result in improper functioning. So, it is advisable for you to keep updated software to get the essentials and keep using the smart device without facing any problems.

There are many users who experience disconnection from the device with the Wi-Fi networks. It mainly happens due to outdated software that you are using. So, you should open the application and check the update tab. Find out if there are any upgrade options available. Update the device if you find any.

10. Check The Y1 Terminal Connections

You will find some if you check the connection in the nest thermostat. Here are some of them.

  • RH power
  • W1 for heat
  • Y1 for cooling
  • C for common wire

While different experts have different recommendations to make, some would say that when you remove and then insert the Y1 cable, it might resolve the cooling issue. So this is one of the tricks you can apply if all the other fixes do not work.

How Can You Factory Reset Your Nest Thermostat?

Now that you have checked all the other ways that you can try to fix the nest thermostat not cooling issue, it is time for you to apply them. However, if none of them really perform well, trying a factory reset sometimes helps to get rid of the glitches happening in the background.

Performing a complete refresh technique can sometimes resolve the problem from its route. However, these are the steps that you can perform to make a factory reset.

  • Using your smartphone, open the NEST
  • Look at the top left corner of the home screen.
  • Choose Home if the devices are connected to multiple houses. Select Home with the particular thermostat that you wish to delete.
  • Click on the thermostat that you would like to remove from your application screen.
  • Visit Settings, available in the upper right corner.
  • Choose to go to the bottom of your screen.
  • Look for option one that says “confirm thermostat” written in red color.
  • Lastly, click to confirm, and you will find the thermostat is removed from the Nest account.

How Can You Force The Nest Thermostat To Hold The Temperature?

If you would like to preset or adjust the temperature on your nest thermostat, the following are some of the steps that you need to perform. Make sure you read them thoroughly and apply them to hold the temperature properly every time.

  • Using the smartphone, open the NEST application.
  • Check the top left corner and press the dots.
  • Choose the thermostat that you want to make a change.
  • Check on the section saying hold temperature.
  • Wait for a while until you have correctly set the thermostat to the count you wish to.


So, these are some of the most common solutions and reasons why you are facing the NEST thermostat not cooling issue. You must know that a loose connection is one of the prime reasons why users face such issues. However, apart from this, there are several other minor issues that can also result in facing the thermostat not cooling issue.

So, now that you have gained some knowledge about the possible fixes for the “nest thermostat not cooling” issue, it will be easier for you to try them and check them. Remember to be very precise when working with the wires.

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