If the screen on your Nest thermostat isn't lighting up or responding, the battery probably needs a charge.
So in most situations, replacing or recharging the batteries on your Nest thermostat will bring it back to life.
However, there can also be another issue, so keep reading to learn more.
Most Common Reason for a Blank Screen With No Lights
The most common reason for a Nest thermostat being unresponsive and displaying no lights or a blank screen is typically due to a power issue, such as a low battery or a wiring problem.
Beyond that, the thermostat may also freeze up during a software update, causing the screen to go blank.
So it’s important to troubleshoot the issue carefully so you can eliminate the most probable causes and get to the root of the problem.
Don’t worry about this because, in the sections that follow, I’ve listed out a comprehensive troubleshooting guide that will help you get your Nest thermostat back up and running.
At SmartHomePerfected we always advise readers not to undertake any work they are not competent in performing and if in any doubt, it is best to seek the assistance of a professional.
Step 1: Try Controlling the Thermostat Remotely
When your Nest thermostat doesn't display any light or signs of life, the first thing you can do is try controlling it remotely.
- Use the Nest app on your smartphone or tablet to check if the thermostat responds.
- By doing so, you can determine whether the issue lies with the thermostat's display or the entire device itself.
- If your Nest thermostat responds to the app, it's probably due to a screen glitch or a broken display.
- Beyond that, the app may notify you if the thermostat is updating
However, if the thermostat remains blank and unresponsive, with the device not responding to the app, the thermostat might be powered down. If that’s the case, I suggest moving over to the next step.
Step 2: Check the Pins and Wiring on the Thermostat Base Plate
When troubleshooting a power issue with a Nest thermostat, the first thing you should do is check the wiring.
- First, remove the thermostat from the wall mount.
- Then take a look at the wiring connections. Make sure they are tight and any thermostat wires aren’t damaged or pinched.
- Also, make sure the connections are wired according to their corresponding terminals.
- If you don’t have a C-wire installed, now would also be a good time to consider setting up a C-wire for your Nest thermostat.
- To fix this issue, start by carefully removing the thermostat display from the base.
- Also, don’t forget to check for any bent pins, dust buildup, or exposed wires.
- If possible, you can also try checking the voltage using a multimeter or the connections at the other end (such as the furnace control board) but make sure to switch off the power before you do.
If everything seems proper, you can try reinstalling the thermostat display or skipping to the next step.
Step 3: Replace or Recharge the Batteries
Depending on your model, you might be able to simply recharge the batteries by plugging them into the power or replacing the batteries entirely. This will help provide power back to the thermostat and restart the screen.
However, if your thermostat doesn't run on batteries or if replacing them doesn't seem to fix the issue, I recommend getting help from a professional or skipping to the next step.
Nest Thermostat (2020 Model)
Smart thermostat
If you've got the latest Nest thermostat, you can simply replace the batteries. Here's how:
- Pull the thermostat from its wall mount/baseplate.
- Flip the device and take out the old batteries from the back.
- After that, insert two new AAA alkaline batteries, making sure the polarities are correct.
- Finally, push the thermostat back into the wall mount. Make sure it clicks into place.
Also, don’t forget to use only high-quality 1.5 V AAA alkaline batteries from a popular brand.
Nest Thermostat E and Learning Models
Smart Thermostats
For these models, you can try recharging the internal battery via a Micro-USB or Mini-USB cable.
Charge the thermostat overnight or for a couple of hours and reinstall it and see if the issue resolves itself.
However, when recharging your Nest Thermostat E or Nest Learning thermostat doesn't seem to resolve the problem, you can consider replacing the batteries or moving to the next step.
Replacing the internal batteries will require you to purchase dedicated Li-Poly batteries (such as the 380mAh TL284443) from an aftermarket manufacturer. These are not very common and Google doesn't recommend you try to replace the internal batteries yourself.
Step 4: Restart the Thermostat
After you’ve rooted out any thermostat power issues, and the thermostat is still blank and unresponsive, you can try force-restarting or resetting the device. However, don’t forget that you will lose all your settings and connections with the mobile app
To force-restart the thermostat:
- Hold the thermostat ring button until the screen turns off (this will only take about 10 seconds). Let go after that.
- Then, press and quickly release the ring button again to turn it back on and complete the restart process.
- Wait until the thermostat fully restarts.
However, if the reset doesn’t fix the issue, you’ll have to move on to the breakers and HVAC system. So if you aren’t comfortable beyond this point, it’s best to call in a professional technician.
Step 5: Check the HVAC System and its Circuit Breakers
If you can’t figure out why your Nest thermostat is malfunctioning, it might be because there’s no power coming into the thermostat or the rest of your HVAC system.
In that case, it’s best to check the breakers, fuses, and any safety switches related to your HVAC system and reset them if necessary.
However, always remember to follow the necessary safety precautions. Turn off the power if you’re diagnosing the inside of the furnace and be careful when flipping any breakers or switches.
Final Step: Get Help from a Professional
If you’re not comfortable diagnosing electrical components or you can’t figure out why the HVAC system is powered down, it’s best to get help from a professional.
An HVAC technician might be able to figure out if your thermostat is defective or if there are any underlying issues with the rest of your HVAC system.
Conclusion
More often than not, a blank display on a Nest thermostat is because of a power failure. In that case, you can get it back up by recharging or replacing the batteries.
However, the thermostat might also be damaged beyond repair, so make sure to check the guide above or get help from a professional as soon as possible.