Nest Thermostat Not Heating or Cooling

If your Nest thermostat is set to heat or cool but nothing is happening, work through these checks before assuming there is a problem with your HVAC system.

1. 1Check the Nest display — if it shows a leaf icon or the word Eco, the thermostat is in Eco mode and is not actively heating or cooling. Press the thermostat ring to wake it up and switch back to Heat or Cool mode.
2. 2Check for a Delay message on the display — Nest shows a "Delayed" message when it is waiting to start the system to protect the compressor. This is normal and will clear within a few minutes.
3. 3Check the temperature setting — make sure the target temperature is actually higher than the current temperature (for heating) or lower (for cooling)
4. 4Check your circuit breaker — if the breaker for your HVAC system tripped, the Nest cannot control it
5. 5Check the air filter — a clogged air filter can cause the HVAC system to shut down as a safety measure. Replace it if it has not been changed in the last 90 days.

Nest Thermostat Showing a Delay

The 'Delayed' message on a Nest thermostat is one of the most common things homeowners worry about — but it is usually not a problem.

• A short delay (2 to 5 minutes) is normal and protects your air conditioner's compressor from damage caused by starting too soon after it last ran
• A longer delay (more than 10 minutes) may indicate a low battery in the Nest or a wiring issue
• If the delay message never clears, check the Nest's battery level in Settings. If the battery is low, the Nest may need to be charged or the C-wire (common wire) may need to be connected to provide continuous power

Nest Thermostat Not Connecting to Wi-Fi

The Nest thermostat needs a Wi-Fi connection to be controlled from your phone and to receive software updates. If it loses its connection, here is how to fix it.

1. 1On the Nest thermostat, press the ring and go to Settings, then Network
2. 2Check whether the Nest is connected to your Wi-Fi network and what signal strength it shows
3. 3If it shows Not Connected, select your Wi-Fi network from the list and enter your password
4. 4If your Wi-Fi password changed recently, you will need to update it on the Nest using the steps above
5. 5Restart your router by unplugging it for 30 seconds and plugging it back in, then check the Nest connection again

Nest Thermostat Running Too Hot or Too Cold

If your home is consistently warmer or cooler than the temperature you set, the Nest may need to be recalibrated or its temperature sensor may be affected by its location.

• Check the Nest's location — if it is in direct sunlight, near a vent, or in a drafty hallway, it will read the wrong temperature for the rest of your home
• Use the Temperature Offset feature in Nest Settings to adjust the displayed temperature up or down to match a thermometer in a central location
• If you have a Nest with room sensors (like the Nest Thermostat E with Nest Temperature Sensors), make sure the sensors are placed in the rooms where you spend the most time

Nest Thermostat Screen Is Black or Not Responding

A black screen or an unresponsive Nest thermostat is usually a power issue.

1. 1Press the thermostat ring firmly to wake it up — the screen may have gone to sleep
2. 2If the screen stays black, the Nest battery may be dead. Remove the Nest from its base (pull it straight off the wall) and charge it using a USB cable (micro-USB for older models, USB-C for newer ones) for about 30 minutes
3. 3If charging does not help, check that the wires on the back of the Nest base are securely connected
4. 4A C-wire (common wire) provides continuous power to the Nest. If your system does not have a C-wire, the Nest relies on its internal battery, which can drain over time. An HVAC technician or smart home installer can add a C-wire.

Resetting a Nest Thermostat

If you have tried everything else and the Nest is still not working correctly, a restart or reset may help.

• Restart (does not erase settings): Press and hold the thermostat ring for about 10 seconds until the screen goes black, then release. The Nest will restart.
• Reset (erases settings): Go to Settings, then Reset, then choose what to reset (Schedule, Network, or All Settings). Only use All Settings if you want to start completely fresh.