A clear and detailed guide on how to charge Nest thermostat

Now there are more and more devices that can help you completely improve the atmosphere in your room and at the same time make it easier to use a huge number of devices for changing temperature, humidity, etc. One such device is the Nest Thermostat, which allows you to control the HVAC system with just your phone fully.

However, due to the peculiarities of its design, many people began to have questions about how to properly charge your Nest thermostat. If this question is relevant to you, then this article will help you. Below you can find not only how to charge your thermostat, but also how to fix a thermostat that is not charging.

What is a Nest thermostat? 

Let’s start with the most important thing, what is a thermostat? The Nest thermostat is a device that connects to the HVAC system and can maintain a comfortable temperature in your home by controlling, for example, an air conditioner.

What’s more, when using Nest Thermostats, you will be able to see exactly what temperature is in your room right now, some models even show the day of the week and humidity percentage. In this way, it will be easier for you to understand whether you need to turn on the air conditioner or heat pump.

What is an HVAC system?

HVAC system is a set of devices that are responsible for heating, ventilation and air conditioning.  In fact, this is a system that is completely responsible for the atmosphere and air quality in your home.  The thermostat is the remote control for this system.  Also, circuit breaker is considered to be the easiest access to power supply for HVAC systems.

What type of batteries does Nest thermostat use? 

Inside the Nest thermostat are two standard AAA alkaline batteries that you can replace. Most often, you can find out about problems with them from the application on the phone connected to the thermostat, but sometimes the thermostat itself notifies you on its screen when the batteries are low.

Nest thermostat E VS Nest learning thermostat 

The Nest thermostat E and Nest Learning Thermostat are the most popular models among Nest thermostats, but they should not be confused with each other and you need to understand the difference between them to choose the thermostat that suits you best.

The Nest Learning Thermostat is more expensive than the Nest Thermostat E, mainly because this model is newer and has almost the same components as, for example, the Nest learning thermostat battery, which is no different from the Regular Nest Thermostat batteries.  

Also, these two thermostats have slightly different capabilities, for example, Nest Thermostat E does not have access to Nest Farsight. Moreover, the Nest Learning Thermostat has access to a higher percentage of 24V heating and cooling systems than the Nest Thermostat E.

However, the difference between them is still insignificant, which is why the methods of recharging and fixing damaged batteries are almost the same. So even if you have a unique Nest Thermostat model, one of the charging methods is likely to work for you.

Nest thermostat battery lifespan 

In general, Nest thermostat internal battery life with a full charge can be discharged in just a few days. However, in general, the Nest Thermostat battery life depends, of course, on how you use it and also on the quality and power of the power supply, from which the battery must receive a constant sufficiently strong energy charge.

If the HVAC power supply for the thermostat battery constantly gives the battery access to the connection, then the battery can easily last even 10 years, but if there is a problem with the power supply and poor-quality connection materials, of course, you will have to change the battery much more often.

Low battery warning 

The most common indication that you need to charge your Nest thermostat battery is either an alert in the app on your smartphone, or you notice a blinking red light on the thermostat itself. How else does a low charge on the thermostat manifest itself?

Firstly, the Nest Thermostat display will be frozen and will not respond to your touches or button presses in any way, since it will not have the resource to execute commands.

Secondly, you will notice that the temperature in the room has become unusual or unusual for you since the Nest battery cannot provide enough charge to the device to control the HVAC system.

Thirdly, your Internet connection will be lost and you will not be able to connect, because as soon as you enter the settings, the screen may be blocked by a blinking red light.

How to charge the Nest thermostat? 

Finally, we come to the main question, how exactly to charge your Nest thermostat? Below you can see the various steps that will help you charge your thermostat successfully and safely.

First method

The first thing you need to do is reset your thermostat and check if it is properly connected to the HVAC system if the common wire is in good condition and so on.

To reset the Nest thermostats, you need to press the button in the form of a ring and hold for a few seconds. And when the Nest thermostat screen turns off, wait a few seconds and press again.

Second method

If you originally installed your Nest thermostat with a C-wire adapter, then you need to check the status of the c-wire. It is best to check the c wire on a regular and routine basis, as this wire is quite fragile and often the thermostat will not charge due to a broken c wire.

If there are problems with the wire, then try reinstalling the thermostat without this wire.

Third method 

You can also try to charge your nest thermostat not with a wall charger, but with a USB cable.

To do this, you need to remove the thermostat from the wall and connect the cable to a reliable power supply, such as a computer.

Fourth method

Perhaps your Nest thermostat cannot be safely charged due to system overload and it urgently needs resetting. To do this, go to the thermostat settings and find the reset button.

Why my Nest thermostat doesn’t charge? 

To be satisfied with using the nest thermostat as much as possible, you need to understand exactly what situations lead to its breakdown. Below you can see the reasons why the thermostat battery won’t charge.

Power outage 

If you experience a power outage and then don’t turn on the Nest Thermostat or check the HVAC wiring, this can cause the thermostat to randomly heat up and cool down the battery and stop charging normally.

HVAC unit 

You should always check the quality and integrity of the HVAC unit, as it is they that provide charge and power to the Nest Thermostat. If you notice that these units are broken, you should either consult the user manual or try to replace them yourself.

Issue with battery 

If your nest thermostat battery is broken, then you should replace it, as attempts to recharge will not be successful.

HVAC fuse

The HVAC system fuse may blow. If such a situation happened to you, it is better to immediately contact the user manual or try to measure it yourself with a new one, the main thing is to know the correct model.

Power supply

In this situation, a transformer with a common wire will help you. Most often, the thermostat battery won’t charge from the power supply if there is an obstacle due to which there is a lack of electricity.

Unique methods to fix nest thermostat that isn’t charging 

If the methods before did not help you charge your Nest battery in any way, then the methods for fixing the Nest Thermostat battery described below may help you:

Warranty period

The easiest way is to get your Nest Thermostat repaired with a warranty. In this method, you can not only get the thermostat fixed, but the company can also change your thermostat if the battery is defective.

Check if the warranty covers up to your period of usage and your situation, then contact the user manual and you can find out more about a possible repair. If your warranty has expired you can still get your Nest Thermostat fixed, however, you will have to pay for it.

C wire adapter

You can also try installing a c wire adapter.

As we said earlier, many Nest thermostats initially come with a c-wire as a charging method, however, if your Nest device was originally installed without a c-wire, perhaps purchasing it can help you solve the charging problem.

Nest Power connector 

Buying a special Nest power connector can help you.

If you understand that the problem of the lack of charge on the nest device is an unstable energy connection, this method is ideal for you.

Replace the nest thermostat battery 

Finally, one of the most effective ways is to simply replace the AAA alkaline batteries in your Nest device.

This method is not available for Nest Thermostat E and Nest Learning Thermostat models. You need to turn the thermostat over after you have removed it from the wall. Find a connector for the Nest battery and just change the old batteries for new ones.

However, if you have a Nest Thermostat E and Nest Learning Thermostat and you realize that the battery inside is broken, the only thing you can do is contact support, as if you try to replace the battery yourself, you can damage the thermostat.


Does Nest thermostat need charging?

Yes, the Nest thermostat needs a constant power supply, but most often it is charged by connecting to the HVAC system, in case of malfunctions, the thermostat can be charged separately using a USB cable.

How do I know my Nest is charged?

The first thing you can check is if you have an app on your smartphone that is connected to the Nest Thermostat. However, even on the thermostat screen itself, you will be able to see that there are no low battery warnings in case of a full charge.

Is Nest thermostat battery rechargeable?

Nest thermostats are initially packaged with rechargeable batteries, especially the Nest Thermostat E and Nest learning thermostat since they do not have a battery changer function, which is why they have a rechargeable battery built into them.

How do I fix my Nest thermostat with low battery?

Nest Thermostat with a low battery is easiest to fix using a USB cable and charge Nest Thermostat manually, as this is the most common way to charge devices. In case your thermostat has a low battery and is not charging, please refer to the user manual.


Nest Thermostat is a device that completely controls the heating, ventilation and air conditioning system in your home. 

However, in order to use this device for as long as possible, you need to better understand how to properly power the thermostat and what to do in cases where there are problems with the batteries, which turn into an obstacle to the flow of electricity.

We hope that after reading this article you have a deeper understanding of exactly how to charge your Nest Thermostat and there are methods for fixing a thermostat that does not charge, like with C wire. You will now be more confident in using the thermostat as an HVAC system control tool.

Read also: Honeywell WiFi thermostat connection problems, how to troubleshoot and fix them?

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