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Nest Thermostat Not Cooling (Read This First!)

A few problems can develop with Nest thermostats causing the system’s cooling to malfunction. So, what are these problems, and how do you fix them? 

Some problems that can cause your Nest cooling system to malfunction include the wiring in the Nest thermostat, miss-identifying the cooling system, a tripped switch in your circuit breaker, problems with the systems software, the common or “C” wire, or the auto-schedule being enabled. 

There seem to be quite a few problems that can affect the cooling system of your Nest thermostat, but these problems are relatively easy to fix. In this article, we will see how to fix all these problems with your Nest thermostat cooling to get your house cooling down in no time!

Why Your Nest Thermostat Might Not Be Cooling Correctly

Thermostats and ACs are a necessary household appliance, especially if you live in areas of the country that has extreme temperatures in the winter and summer months. Nest thermostat systems are popular due to their ease of use and greater control, but there can be some issues with the product. 

There have been multiple accounts of people struggling with the cooling part of the system. A few things can cause this problem, so let’s go through the causes and how to fix them to get your home cooling down properly in the hot summer months. 

The Wiring In The Nest Thermostat 

One of the main reasons a Nest thermostat might not be cooling correctly is the wiring in the thermostat itself. So, this should be one of the first places you check when you have this problem. 

The Nest thermostat can contain loose or bulk wiring that can cause damage to your thermostat and stop the system from cooling properly. 

Solution: Check The Wires 

The solution to this problem is to check the wires in the thermostat itself. You will first need to turn off the power supply to your home to ensure you are safe while working with the wires. Once the power is off, carefully take the display screen off the thermostat device.

Check all the wires and ensure they are secured tightly into their correct positions. Ensure the wires are well organized to prevent any unnecessary tugging of the wires and that the wires don’t touch in the wrong places, which can lead to a short circuit. 

Place the display screen securely back in place and turn your power back on. Wait a few minutes and turn the thermostat back on. See if your cooling works now. If it’s still not working, move on to the next possible cause. 

Miss-Identifying Your Cooling System

One possible reason that the cooling might not be working is that you have made a mistake in identifying the cooling system you have. Don’t worry; this is a very common problem that many people face. 

Solution: Identify Your Cooling System 

You need to confirm the type of cooling system you have installed in your home, as this will affect the way your thermostat should be wired. For example, if you have a heat pump system installed but wired in the conventional or old thermostat rows, your heat pump thermostat won’t work correctly. 

To identify the type of system you have in your home, you can check the backend of your home device. These sections should have identifying markers such as a product label, manufacturing details, and system class. 

If you are still unable to identify your home system, you can do an internet search with the model number of your system, which should tell you which one you have. You can then wire the system accordingly. 

A Flipped Switch In Your Homes Circuit Breaker

Your home’s circuit breaker is one thing you can check if you are having problems with your thermostat. Switches in the circuit breaker can trip unexpectedly and cause malfunctions in devices in certain locations of your home, including your thermostat. 

Many people also turn off certain switches on their circuit breaker for various reasons, and when they have their thermostat installed, they forget to turn the switch connected to it back on. 

Solution: Check Your Circuit Breaker

You need to go and check your home’s circuit breaker and ensure all the necessary switches are turned on. If the one connected to your thermostat has tripped or is turned off, you need to turn it back on. 

You cannot flip the switch as is; you must turn the mains off first to switch off your circuit box. Then flip all the switches off and slowly tune them on one at a time. Once all the necessary switches are on, turn the main switch back on. Wait a few minutes, then turn your thermostat on and see if it works. 

Problems With The Common Wire 

Inside the thermostat, there is a wire called the common wire or the C wire. This wire allows 24 VAC power to continuously flow through to the thermostat you have installed. With the Nest thermostat, this wire comes pre-installed in the device. 

This wire can cause problems with the thermostat, especially the cooling options. Many say disconnecting this wire has solved their cooling problem with the Nest thermostat. 

Solution: Disconnect The Common Wire

You can disconnect the common wire of the device pretty easily. First, you must switch off your house’s power at the circuit breaker for your safety. Then locate and open the wiring chamber in the thermostat. 

You will see that there are a few wires already connected. These are the W1, Y1, RH-power, and the C or common wire. Carefully disconnect the common wire from the device and leave the device for a few minutes. 

Then place the cover back on and turn the thermostat on. Check if your thermostat cooling is working now. 

The Thermostats System Could Be Slowing Down

One problem that can cause the cooling of your Nest thermostat to malfunction is the system’s software. The Nest system can get overloaded or outdated, which can cause problems with how the system functions. 

Solution: Update And Restart The System

If you think this is the reason for the cooling problem with your Nest thermostat, then you need to check and see if there is a software update that you have not installed for the system yet. If so, update the system and leave it for about five minutes. 

When this time is up, you can restart the system entirely. If this was the cause of the cooling malfunction, it should be fixed after this. 

An Enabled Auto-Schedule

Your Nest thermostat might not be engaging the cooling system when required because the auto-schedule has been enabled on the system. The Nest thermostat includes an eco-friendly feature that controls the temperature remotely. 

Many users of this thermostat turn this feature on and forget that they have enabled it. This means that the system will cool as it presets, which can sometimes happen with a lack of temperature. The system will technically be cooling, but no cold air is released into your home.

Solution: Disable The Auto-Schedule

To fix this problem, you will need to disable the auto-schedule in your system. There are two ways you can disable this schedule. You need to open the Nest application on your mobile device for both options. 

Then you can find the ECO-Temperature option on the application and turn this option off. Alternatively, you can use the Auto-Scheduling option and turn the schedule off. Then you can turn your Nest thermostat on and see if the cooling works correctly. 


The Nest thermostat is a great option for your home, even though there can be some problems that can occur. Most of the issues are to do with the cooling part of the system, but they are generally easy to fix. 

If you follow the advice in this article and troubleshoot to find out which of these problems above are causing the cooling problem, then you should have your Nest thermostats cooling up and running in no time. Good luck with your Nest thermostat!