Question 1

nest keeps switching to eco mode when i'm home, even though i have home/away assist off.

Accepted Answer

DIAGNOSIS The Nest's built-in occupancy sensor isn't detecting you, or your phone's location isn't being used correctly for Home/Away. FIX First, turn off all auto-scheduling features. Go to Settings > Auto-Schedule and turn it OFF. Then, go to Settings > Home/Away Assist. Turn off 'Use phone location'. Also turn off 'What decides if you're home' and uncheck the Nest thermostat sensor itself. Manually set a temperature and see if it holds. IF THAT DIDN'T WORK Check for conflicting schedules. A leftover schedule from Auto-Schedule or a manual entry can still trigger temperature changes. Go to Settings > Reset > Schedule and select 'Reset'. This clears all scheduled setpoints. Then set your desired temperature manually. HEADS UP If you have multiple Nests, ensure they aren't in a 'Nest Together' group where one's occupancy sensor controls all of them. Also, bright sunlight hitting the Nest's face can trick the sensor into thinking no one is there.

Question 2

my nest says 'in 2+ hours' for cooling to reach the temperature, but it never gets there.

Accepted Answer

DIAGNOSIS Your air conditioning system is undersized, low on refrigerant, or has a airflow blockage. The Nest is calculating the time based on how slowly the temperature is dropping. FIX Check your air filter. A clogged filter is the most common cause. Replace it if it's dirty. Then, go outside and check the outdoor condenser unit. Ensure the coils are not clogged with leaves or dirt and that the fan is spinning. IF THAT DIDN'T WORK The system may be low on refrigerant or have a failing component. The Nest is accurate—if it's taking forever to cool, the system isn't producing enough cold air. Listen for the compressor cycling on and off quickly (short cycling), which indicates a refrigerant issue. HEADS UP This is not a thermostat problem. Continuously running an AC that can't keep up can freeze the evaporator coil and cause compressor failure. Call for AC service.

Question 3

how do i clean the screen? it's got fingerprints and smudges and the ring isn't responding well.

Accepted Answer

DIAGNOSIS Oils and dirt on the glass and the capacitive touch ring are interfering with the touch sensor. FIX Power down the thermostat by pulling it off its base. Use a microfiber cloth, slightly dampened with water only. Gently wipe the entire glass face and the stainless steel ring. Dry it completely with another clean, dry microfiber cloth. Do not reattach until it's 100% dry. IF THAT DIDN'T WORK If the ring is still unresponsive, there may be a hardware fault in the capacitive sensor. After cleaning, perform a hard reset. Press and hold the ring for 10 seconds until the screen goes blank and restarts. This reboots the touch controller. HEADS UP Never use cleaning sprays, window cleaner, solvents, or abrasive cloths. They can damage the oleophobic coating on the glass and permanently ruin the touch sensitivity. Water only on a soft cloth.

Question 4

nest keeps disconnecting from wifi every day, i have to keep re-adding it.

Accepted Answer

DIAGNOSIS Weak or unstable Wi-Fi signal at the thermostat location. The 3rd Gen Nest has a weaker radio than some routers. FIX Restart your router and modem. Then, on the Nest, go to Settings > Reset > Network. Choose 'Restart' first. If that doesn't hold, do a full 'Forget Network' and re-add it. Ensure you're on a 2.4GHz network band, not 5GHz. IF THAT DIDN'T WORK The distance or obstructions (walls, metal ducts) are too great. Use a Wi-Fi extender. Place it halfway between your router and the Nest. Set the extender to broadcast the exact same network name (SSID) and password as your main network for easiest reconnection. HEADS UP If your router uses 'band steering' or a single name for both 2.4GHz and 5GHz, it can confuse the Nest. Go into your router settings and create a separate, dedicated 2.4GHz network with a different name just for the Nest.

Question 5

i get error e195 on my nest, something about power sharing? my heat won't run.

Accepted Answer

DIAGNOSIS The Nest detected an issue with the 'Power Sharing' feature used with certain heat pump systems. It's protecting the system from a short cycle. FIX This is usually a wiring or configuration error. In the Nest app, go to Settings > Equipment. Check if your system is configured correctly as a heat pump. If you have auxiliary heat (like electric strips), ensure the 'O/B' connector setting (for the reversing valve) is correct for your brand—O for most, B for some. IF THAT DIDN'T WORK The error can trigger if the Nest's internal temperature sensor thinks the air coming from the system is too hot, indicating a stuck reversing valve or failed aux heat control. You may need an HVAC tech to check the heat pump's reversing valve solenoid. HEADS UP Ignoring this and trying to reset can damage expensive heat pump components. If you didn't install it yourself, get the original installer back to verify the wiring and configuration.

Question 6

why is my nest making a loud clicking sound every few minutes? it's coming from the unit itself.

Accepted Answer

DIAGNOSIS That's the internal relay clicking on and off. It's normal when the thermostat is calling for heat or cool and your HVAC system isn't responding. FIX The Nest is sending the signal, but the system isn't turning on. Check your HVAC system's power. Ensure the furnace/air handler breaker is on and the service switch is flipped up. Also check the condensate overflow switch if you have an AC—if it's full, it will cut power. IF THAT DIDN'T WORK There may be a wiring issue. The Nest's relay clicks because it's trying to complete a circuit that's broken. Pull the Nest off the base and inspect the wires for the 'Y1' (cooling) or 'W1' (heating) terminals. A loose wire here causes this. HEADS UP Continuous rapid clicking can wear the relay. This is a sign your HVAC equipment isn't receiving the signal. The problem is almost always at the furnace/air handler, not the Nest.

Question 7

nest keeps saying 'delayed for 2 hours' and my house is freezing, what gives?

Accepted Answer

DIAGNOSIS The Nest is in a safety lockout mode. It detected a problem with your furnace and shut it down to prevent damage. Usually a flame sensor issue or limit switch trip. FIX Go to your furnace and turn the power off at the switch or breaker for 30 seconds. Turn it back on. This resets the furnace's control board. The Nest should try to start the furnace again. If it runs, the problem was a temporary limit switch trip. IF THAT DIDN'T WORK The furnace itself has a fault. The Nest is just the messenger. Check your furnace's status light. A blinking LED code on the furnace board tells you the real problem—often a dirty flame sensor. HEADS UP Do not keep forcing the Nest to restart heat. If the furnace has a hard fault, you could damage the heat exchanger. Call an HVAC tech if the reset doesn't clear it.

Question 8

my nest thermostat screen is just black and won't turn on, no lights nothing.

Accepted Answer

DIAGNOSIS The thermostat isn't getting power from your HVAC system's C-wire or the internal battery is dead. This is a power issue. FIX Pull the thermostat off its base. Check the connectors on the back of the thermostat and the wires in the wall plate. Ensure the wire labeled 'C' is seated firmly. Reattach the thermostat. If the screen lights up, the connection was loose. IF THAT DIDN'T WORK Your system may not have a C-wire. The Nest was running on its internal battery, which is now depleted. You need to charge it. Use the Nest's USB cable and plug it into the micro-USB port on the back of the display. Charge it for at least an hour, then reinstall. HEADS UP If you don't have a C-wire and this happens repeatedly, you'll need to install a C-wire adapter or use a common wire kit. Running without a C-wire will kill the battery over time.

Google Nest Learning Thermostat 3rd Generation

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