Nest thermostats are some of the best smart thermostats out there. But as with any type of device, they have some common issues that cause them to malfunction. Luckily, there are some easy DIY fixes for our handy readers.
Some common problems with Nest thermostats include the following:
- It suddenly turns on and off, it won’t shut off, or the thermostat display doesn’t respond and won’t light up.
- The motion sensor isn’t working.
- It’s showing the wrong temperature.
- It’s not properly controlling the heating and/or cooling unit.
- The device short cycles the furnace and/or air conditioning units.
- It signals a low battery and requires shut down.
- The app shows the device is offline and disconnected from Wi-Fi.
- It makes clicking or thumping noises.
Common Solutions for Nest Thermostat
As you read through the different problems a Nest thermostat experiences, you’ll notice many of them have similar solutions. Oftentimes, the solutions to the problems include re-wiring, charging the battery (or adding a wire to keep it charged), or restarting the device.
Problem: Turns On/Off Suddenly, Won’t Shut Off, or Display Won’t Respond/Light Up
All of these problems most likely stem from a power issue, meaning the device is not fully charged.
The Fix: Take the Nest off the base and charge it with a USB cable either into a wall outlet or into your computer. Give it at least 1 hour to charge. If it turns on after a few minutes, shut it down and turn it on again. This restarts the device. Now, let it continue its charge.
After it’s fully charged, it should go back to working normally. However, if it’s a bit sluggish, try restarting it one more time.
Problem: Incorrect Temperature Reading
The Wi-Fi chip is sensitive to other heat-generating elements. If your Nest is placed anywhere near air vents, hot water pipes, or electrical outlets, it’s possible that the Wi-Fi chip is overheated. This causes an inaccurate temperature reading.
The Fix: Google Support recommends you install your Nest in an area where it can still communicate with the Heat Link. Place the thermostat ¾ to 1 meter above the floor. If it’s too low on the wall, you may also get an inaccurate reading because cool air stays low to the ground while heat rises.
While you’re looking for the best place to install the thermostat, be aware of any vents, outlets, and hot water pipes. Try to avoid placing the Nest near them.
Problem: Unresponsive Motion Sensor
When you walk by your Nest, the motion sensor should activate, causing the face of the device to light up. If this doesn’t happen, it could be that it froze during a software update, or there might be a power issue.
The Fix: Try charging the Nest completely or restart the device.
Problem: Not Controlling Heating/Cooling Unit
Is your heat setting on but the Nest is blowing cold air? Does it blow hot air when it should blow cold? Perhaps it stops cooling altogether. Each of these scenarios is due to a wiring issue.
The Fix: If it blows hot air when it should blow cold, the Nest wasn’t wired to the heat pump row. Check the Nest website or the Nest app to find the interactive wiring guide. Follow this guide to properly wire the device.
If it stops cooling, the C connector is not properly attached to the system. The thermostat diagram will show you how all the wires should be connected.
If it blows cold air when it should blow hot, check the O/B wire orientation setting and adjust.
Problem: Short Cycling
Short cycling is when your heater or air conditioner shuts off before it reaches the target temperature. When this happens in a home with a Nest thermostat, it can be due to a few reasons.
Reason #1
First, your heating or cooling unit may short cycle when the Nest battery’s voltage drops too low. The Nest’s battery should recharge itself using your HVAC system’s wiring. If this doesn’t happen and it gets too low, the Nest can no longer operate the unit properly. This tends to happen when the Nest is hooked up without a common wire.
The Fix: Add a common wire which provides the Nest with a small amount of voltage. This is enough to keep the system charged.
Reason #2
Another reason your HVAC system might be short cycling is that the Nest is very sensitive to power interruptions. Some types of heating and cooling units turn on and off intermittently if their condensation collection area is full or almost full. The Nest jumps the gun and stops the heating or cooling cycle and moves to the delayed cycle because it thinks it’s lost power.
The Fix: You can get around Nest’s sensitivity to power interruptions by installing a 24 volt AC adapter. This also provides constant power to the Nest’s battery, keeping it fully charged.
Problem: Low Battery Signal
As mentioned in the short cycling problem above, the Nest’s battery should automatically recharge. If it doesn’t, the voltage will get too low. A low battery signal is most likely due to a wiring problem.
The Fix: Add a common wire to give the battery a bit more voltage.
Problem: Offline and Disconnected from Wi-Fi
When the battery life gets too low, the thermostat goes offline as a failsafe. Although it should continue to charge itself, Wi-Fi drains the Nest’s battery life. It preserves the rest of its life by disconnecting from Wi-Fi so it can continue to run the HVAC system.
The Fix: First, use any of the above-mentioned solutions to fix the battery charging issue. Next, you can bring the thermostat back online from the app by going to Settings > Reset > Network > Confirm. Once you’ve reset, go back into Settings > Network and follow the directions to reconnect the thermostat to your Wi-Fi.
Problem: Thermostat Makes Noise
Your Nest thermostat could be making noise for a couple of reasons. If it sounds like it’s clicking or thumping, the system is probably turning on and off too quickly. If you hear a buzzing from the thermostat, the device could be experiencing an over-current.
The Fix: The clicking and thumping sound can be resolved by connecting a C wire to the Nest thermostat. The over-current errors that cause buzzing are generally due to miswiring or a worn part on the system’s control board. This should be handled by a service professional.
Related Questions
What is the average lifespan for a Nest thermostat?
A Nest thermostat should last up to 10 years.
How do I know my Nest thermostat is charging?
A lot of our solutions to the common problems of Nest thermostats involved charging the device. You’ll know it’s charging if you see a blinking red light at the top of the thermostat.
What does resetting a Nest thermostat do?
Similarly, many solutions involved resetting the device. This erases any personal information or settings you input and restores the Nest to its factory setting. You would need to update all this information should you need to reset the thermostat. While it’s annoying, sometimes, resetting is the only solution. On a side note, you need to reset the device if you decide to move it to a different location.
Conclusion
It’s frustrating when a smart device suddenly stops acting smart! Many Nest thermostat users found common problems with their devices, but thankfully, they are easily fixed. Anyone can reset a Nest thermostat. And those who are a little handier can attempt re-wiring the device.
