Troubleshooting common problems with Nest thermostat
1. Nest thermostat heating instead of cooling
You may often experience overheating problems with your Nest thermostat. Your system may unexpectedly produce hot air instead of a cold one.
This happens when there is some unfortunate error with your wiring system. For example, the wires may overlap and cross, resulting in such an issue.
Below are the steps to tackle Nest thermostat heating instead of cooling:
- Firstly, turn off the breakers.
- Next, take a picture of the wiring for reference after fixing it.
- Now change the wiring according to the correct installation guide. You may even head to the Nest app and get assistance through the interactive wiring guide for your ease.
2. Low battery life
Not sure why you’re frequently encountering low battery issues? This may occur due to multiple reasons, which you can luckily fix. Moreover, there are certain consequences for such an error like Wi-Fi connectivity problems, thermostat not turning on, and much more.
Therefore, it’s essential first to rule out the main cause of frequent low battery life, which may aid you in preventing all the problems associated with this issue. So, to do so, you need to check your Nest battery’s status first.
Below are the steps to check the Nest battery’s status:
- Firstly, head to
- Next, scroll down to technical info and check the power settings. Note that there may be various settings, but our main concern is battery level and voltage.
- So, if your battery level is above 3.6 V with 20 mA or above current flow, then it’s perfectly fine. However, if it’s below it, you must fix the issue.
Now, suppose you discover the low battery status of your Nest thermostat. In that case, you may solve such an issue by the steps given below:
- Try connecting the G wire to the C terminal: This hack may help you continuously charge your Nest thermostat. However, you need to remove the G wire and connect it to the C terminal in your HVAC system for absolute results.
- Try charging your Nest device using a USB cable: This hack may go well, especially when your AC system has been off for a long time. By doing so, your battery will get a boost and thus will work efficiently. So, get a regular phone charger and connect your device for about one to two hours for good results.
- Try using a 24 V common wire transformer: If your HVAC system is not providing sufficient power to your system. Then this hack is surely life-saving. Connect the transformer to your thermostat using its two wires to the Rh and C terminals.
3. Nest thermostat disconnected from Wi-Fi
Your thermostat may recurrently disconnect from Wi-Fi due to a low battery problem, the problem with the Nest service, or Wi-Fi not working efficiently. You need to follow some troubleshooting hacks in all these cases to get rid of them.
Here are the steps to fix the Nest thermostat disconnected from Wi-Fi:
- Try restarting your router: Restarting your router may work as rebooting or refreshing your device in no time. It will fix all the concerns related to your Wi-Fi. This will also help you determine whether the issue was behind the thermostat or the Wi-Fi device.
- Try connecting the C wire: This hack may help solve the Nest thermostat low battery no Wi-Fi issue. You may simply get a new wire and connect it to the C wire slot or remove the G wire and fix it. In both ways, you will improve your problem. However, if you opt for the second option, you may also need to do the same with your HVAC system.
- Try resetting your Nest’s Wi-Fi connection: You may just disconnect your Nest thermostat from the home App and set it up again. This will help refresh the whole system and will thus solve your problem.
4. Nest thermostat no power to Rh wire
If your system shows an E74 error message and can’t draw power, then the problem is possible with the Rh wire. The system may trip either one of the breakers, Nest may inefficiently connect the Rh and Rc wires, or there may be a blown-up fuse in the air handler.
Here are the solutions to the Nest no power to Rh wire problems:
- Turn the breaker off and on: Firstly, check if your breakers are fine. If they have tripped, switch the breaker off and on. Verify if your system is now powered on or not.
- Try putting a red wire in the Rc port: Firstly, check if your Rh and Rc wires are connected well. However, if you have only one wire, then make sure you have connected it to the Rh port. If, even after doing so, you didn’t get the power, then try putting the red wire in the Rc port.
- Replace the blown-up fuse: If you have blown a fuse, just replace it and check the results.
5. Why does my Nest say delayed?
Your Nest thermostat may show delays when experiencing issues with the battery or the common wire. So, to deal with this trouble, ensure that your Nest system has a proper C wire connection that may enable you to charge your thermostat continuously without any hurdle.
Moreover, if the problem lies behind the C wire, you’ll need to contact the HVAC technician to resolve the issue.
6. Nest thermostat flashing green light
Another problem is the Nest thermostat blinking green light. The Green light on Nest Thermostat indicates a software update, system start, or restart. Thus, it may last for a few minutes, mainly one or two.
However, it is a big deal if your Nest is flashing green light with a black screen. The black screen indicates that your system is unresponsive as it has frozen.
To deal with this situation, simply remove your Nest device from the base and put it back again. You may even press your thermostat button for a few minutes to restart it. Both ways may help you resolve this problem within a few minutes.
7. Nest thermostat fan not working
If you notice your Nest thermostat turning its fan on and off, it surely is a red flag. This will cause all the water to be drawn back into your house instead of blowing it outside.
This, in short, affects the functioning of the Air-conditioner because of the accumulation of excessive moisture in the system. It may then affect your thermostat and HVAC system as well.
Below are the steps to fix the Nest thermostat fan not working:
- Firstly, restart your Nest thermostat.
- Next, reset it to the factory
- Now, turn the fan of your AC off.
- Cut the power to the furnace.
- Lastly, swap the wires at the terminal such that G wire into the Y1 terminal and Y1 wire into the G terminal. However, make sure you turn off the breakers before performing this step.
Also, don’t forget to turn your Nest display on and turn your breakers on.
These steps will make your fan work properly. Thus, the cooling system will start functioning.
8. Nest thermostat cycling on and off
Don’t know why your Nest thermostat turns off before reaching the required temperature? This may occur due to the furnace issue. Also, dirt may clog your air filters, resulting in this frustrating issue.
Below are a few reasons that may cause your thermostat to cycle on and off:
- Faulty Nest thermostat.
- Air filters are clogged with dust.
- Poorly insulated furnace.
- Oversized furnace.
- Overheated furnace.
- Corroded or problematic flame sensors within your HVAC system.
So, to rule out the main cause, it is essential first to check the Settings of your system and make sure they’re correct. Next, have a clear look at the furnace and try to solve the problem accordingly. However, if you don’t have any issues, don’t hesitate to call your technician for further assistance and repair.
9. Your thermostat turning on and off
We understand how annoying it would be for you when your thermostat keeps turning on and off. But, unfortunately, this may happen not just because of the faulty thermostat. But also due to trouble with the HVAC system.
For instance, if your air filters are clogging up, AC may shut down. Further, the Nest thermostat may not be able to draw enough power to charge its battery. As a result, your thermostat will destabilize.
The solution for Nest thermostat keeps turning off includes cleaning the air filters and charging your thermostat using the USB cable. However, if it doesn’t help you, then contact the HVAC technician for further investigation and repair.
10. Nest temperature sensor not connecting
Another common problem with your thermostat may be sensor failure. For example, your nest sensor may simply not connect due to the app’s inability to recognize the sensor, miscommunication between the thermostat and the sensor, or a heating or cooling problem with the system.
Here are the steps to fix the Nest temperature sensor not connecting:
- Firstly, make sure you have placed your sensor in the appropriate place. Suppose you have placed it near the window. In that case, chances are temperature fluctuations may cause your detector to not the signal accurately, resulting in either a cool or overheated room.
- Next, make sure your sensors are active. To do so, head to the Nest app and confirm the activity of the sensors.
Your Nest button may stop clicking after the first setup. Unfortunately, this is a pretty common problem and may require your system to manually reboot. This hurdle may usually occur when your wires are rather long and thus get in the way. Therefore, the only way to tackle it is to clip these wires and control their length.
Another cause for the button not clicking may include an unsecured mounting disk on the wall. On the other hand, long wires may be the reason behind it.
Therefore, the definitive solution may be to rewire these wires using a wire cutter and rewire them. Ensure to take photographs of the wiring system before working on them to avoid confusion while restriping them.
Once the workup is done, press the thermostat at the base, and if it responds, you’ve solved the problem.
12. Nest thermostat not getting power
Another common issue is the Nest thermostat not getting power, mainly due to wiring issues. Other causes may include a thermostat not connected to a C or common wire, powered off HVAC system at the circuit breaker, fuse box, and system switch.
Below are the troubleshooting steps for the Nest thermostat not turning on:
- If you receive an alert for low battery, then simply charge your system or change the batteries.
- If you recently turned the power off your cooling and heating system at the circuit breaker. Then don’t forget to turn it on.
- If you’re installing the Nest Power connector and then receive the N260 help code, ensure that your HVAC system’s cover is closed.
13. Nest thermostat not turning on the heat
Sometimes your heating or cooling system may show an error. For example, the system remains on all the time, does not turn on when required, turns off unexpectedly, and much more.
You may need to change your thermostat’s settings to tackle this issue.
Here are the steps to fix Nest not turning on heat:
- Head to the Nest Home app.
- Next, tap on the
- Now, tap on Settings at the top right corner.
- There, select the
- Scroll down and tap on the Heat pump. Now, if you have selected option O, select option B Similarly, if you have chosen option B, select option O instead.
- Test your system to ensure the problem is resolved.
14. Nest is not reaching the target temperature
Not sure why your Nest not reaching the target temperature? This may happen due to certain issues related to it.
This may even happen when your thermostat and system both are perfectly fine. However, there still may be a slight difference in the temperature shown and what you feel. However, suppose the temperature difference is way too much. In that case, there may be some trouble with the battery, wiring, or the Wi-Fi connection.
Below are some of the causes for Nest not reaching the required temperature with normal systems:
- Your temperature sensor may be at the wrong location, such as the cold or the hot spot.
- Your system may continuously run for a short time.
- Your home may itself take time to cool or warm up.
- Your nest thermostat may show a rounded temperature.
- Your thermostat may be taking time to learn your heating and cooling schedule.
- There may be a short delay for your system to turn on.
15. Nest thermostat keeps restarting
Are you facing a sudden restart or reboot of your Nest thermostat on its own? This mainly happens due to a blown-up fuse or Wi-Fi connectivity error.
Some other causes for this issue include:
- The display is not sealed accurately.
- The system may have a blown-up fuse.
- Improper Wi-Fi connection
- Improper fixation of the Nest thermostat on the wall.
- Power is not supplied to the device properly.
So, below are the steps to fix this issue:
- Firstly, check the connectors that they have seated properly. If not, then replace the connectors immediately.
- Improper wiring may also cause your system to restart frequently. Therefore, simply repair or readjust the wiring as early as possible to avoid any mishap.
- Your system at home may even have a blown-up fuse. Therefore, if you don’t receive the right amount of voltage, simply fix it before it’s too late.
- Connect your device to the Wi-Fi and give it a quick on-off. This may fix this rebooting or restarting issue in no time.
16. Nest no power to RC wire
No power to the RC wire may appear as the E73 error. This may occur when you have any sort of problem with your wiring, air filter, drain tubes, or HVAC system.
So, to fix such an issue, check all the wiring and drain tubes. Ensure there is no problem with the HVAC system, and your air filter is clean. You may even follow troubleshooting steps to fix the Nest thermostat no power to Rh wire issue.
However, firstly, check the Rc wire status. If you have lost the power to it, then follow the steps given below:
- Turn the power off to your AC unit.
- Then, locate the HVAC system’s air handler’s condensation drain line.
- Next, find the condensation overflow switch.
- Now remove the button. Have a clear look at it and then clean it up.
- Lastly, clean the drain line. Flow some water through it and then test the condensation drain line.
17. Nest no power to C wire
Nest no power to C wire mainly occur when there is a connection problem with your wires. Also, you may inaccurately enter your wire into the app.
Therefore, the only solution to such a problem is to ensure all the wires are connected well and entered properly. But, first, ensure you turn your system off before checking the cables.
Did you just notice red blinking light on your Nest thermostat? The red blinking light on Nest appears due to the low battery of your Nest thermostat. This light may automatically turn on once your battery gets charged.
In addition, to speed up this process, you may disconnect your Nest thermostat and then plug the USB port into your device.
19. Nest E74 error
The E74 error indicates no power to the Rh wire. Therefore, you just need to check the connection of the Rh wire, whether they’re in a place or not. If not, then reconnect them to fix this issue in no time.
20. Nest app not syncing with the thermostat
Nest app not syncing with the thermostat may occur for multiple reasons. These include using an incorrect SSID or password for your Wi-Fi network when setting up your Nest thermostat.
Simply restart your phone or tablet and re-open the Nest app to deal with this situation. First, make sure you have enabled both the Bluetooth and the Wi-Fi network before connecting your Nest thermostat.
21. Nest thermostat not charging
Last but not least, your thermostat may not charge. Nest not charging means your battery is draining pretty quickly. Therefore, leave your Nest thermostat battery to charge for some time manually using a USB cord. This will help it achieve the threshold it needs to stay in working mode.
But before doing so, ensure your Nest thermostat is drawing enough power from the HVAC system; otherwise, the problem may lead to some error within the HVAC system or the wiring.
There are certain common problems associated with your Nest thermostat that you may face frequently. Unfortunately, most of them are interlinked, for example, low battery and poor Wi-Fi connection.
So, if you ever encounter any problem concerning your system, try to find its main cause before heading to its fixes. Therefore, this article discusses all the common issues concerning your Nest thermostat and its causes and fixes to help you eliminate them and avoid them efficiently.