Nest Learning Thermostat 2nd Generation Troubleshooting

The Nest won't respond or show anything on the LCD

A blinking green light will appear if the Nest is turning on, restarting, or updating. If the lights continue to blink for more than 5 minutes, remove and reconnect the display. If the light is still blinking after reconnecting the device, restart it by holding down the thermostat ring for 10 seconds.

A blinking red light will appear if the Nest's battery is too low to start. This could be due to a wiring problem or extended power outage. The Nest should charge itself within a few hours but you can speed up this process by using a micro-USB cable. To do this: remove the Nest display, connect one end of the micro-USB cable into the Nest and the other end into a powered-on computer or USB wall charger.

A blinking green light could mean a common C wire is attached. The common C wire is not needed in most homes for the Nest to work properly. To remove the common C wire:

1. Turn off the power to your HVAC system or home
2. Remove the Nest's display
3. Push and hold the gray spring-loaded tab next to the letter "C"
4. Pull the C wire out of the connector
5. Insulate the copper tip with a cap or electrical tape and push the wire back into the wall
6. Reattach the display and turn the power back on

A blinking green light could mean the wires are not properly attached. To make sure the wires are properly attached:

1. Turn off the power to your HVAC system or home
2. Remove the Nest's display
3. Push and hold the gray spring-loaded tab of the connector's wire you wish to remove and pull the wire
4. Ensure the wire is straight and has 1/3" to 1/2" of copper exposed
5. Seat the wires fully into the connector by holding down the gray spring-loaded tab and pushing the wire into the connector as far as it will go
6. Reattach the display and turn the power back on

If the Nest's display is fully seated to the base, the light at the top is off, and the LCD isn't showing anything, a faulty battery may be the cause. For step-by-step instructions on how to replace the battery, follow this guide.

If the Nest's display is fully seated to the base, the light at the top is off, and the LCD isn't showing anything, a faulty or broken LCD may be the cause. For step-by-step instructions on how to replace the LCD, follow this guide.

The Nest's auto-away function isn't automatically adjusting its settings when you leave or come home

If after learning your schedule, Nest is no longer going into auto-away mode, a faulty auto-away board may be the cause. For step-by-step instructions on how to replace the auto-away sensor, follow this guide.

Nothing happens when metal ring around the display is rotated

To change settings on the Nest Thermostat, a metal ring around the display is rotated. If rotating the outer ring no longer adjusts the settings, a faulty optical sensor may be the cause. For step-by-step instructions on how to replace the optical motion finger sensor, follow this guide.

Wait for a period of 30 to 60 seconds for the thermostat to scan for other networks.

Try resetting your router.

Check if your network is hidden. If so, select TYPE NAME (then type your network’s SSID and password). Next, choose your security type, after which you will be prompted.

Try another Wi-Fi device to verify your network is visible.

Is the router set up to support the Nest? Check if router is set up to support the Nest (make sure you are NOT using 5GHz mode).

Restart your Nest.

Check for Wireless interference (turn off devices that could cause interference, such as cordless phones, baby monitors, and microwaves).

Enter password again.

Try connecting using another Wi-Fi device.

Restart your Nest.

Reduce the number of wireless devices connect to network.

Reset your Wi-Fi router.

Temporarily turn off wireless security on router.

Turn off MAC address filtering on your Wi-Fi router.

Update firmware on your router.

Check your Nest battery in Nest, it may be low.

Check your Wi-Fi signal strength, it may be too weak. If so, you should consider the possibility of relocating either the Nest Thermostat or your router in order to improve signal strength.

Your network may be down due to a power outage. If so, wait for power to resume.

Check with your Internet service provider to see there are any network outages. If so, wait for ISP connection to resume.

Restart your Wi-Fi router (unplug and wait a few seconds, then plug them back in).

Have you changed your Wi-Fi name or password recently? If so, update the Wi-Fi settings on your Nest Thermostat.

Try resetting the thermostat. If that doesn't resolve the issue, it is possible that the AC is constantly cycling because the base motherboard is bad and must be replaced. For step-by-step instructions on how to replace the base motherboard, follow this guide.

Try resetting the thermostat. If that doesn't resolve the issue, it is possible that the AC is running too hot or too cold because the base motherboard is bad and must be replaced. For step-by-step instructions on how to replace the base motherboard, follow this guide.

Try resetting the thermostat. If that doesn't resolve the issue, it is possible that the AC is constantly on because the base motherboard is bad and must be replaced. For step-by-step instructions on how to replace the base motherboard, follow this guide.