Operating a Nest thermostat is one of the most convenient ways to optimize the day-to-day schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make changes. But as you may expect, it won’t work correctly or at all if you see an error code show up. The specific error code supplies useful information about the source of the problem, something a professional technician can use to offer solutions that much quicker.

Here are seven of the most frequent error codes you could encounter on your Nest thermostat. We’ll review the basics of each error code as well as how you can address it and the approximate cost to do so. Keep in mind that while the price will ultimately depend on the exact Nest model, you can expect to pay about $75-$200 for repairs. This should include travel and labor costs along with any specific hardware necessary to complete repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and shows up when the power is shut off. Since this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on display until the issue is dealt with.

Losing power to your Nest thermostat can be for numerous reasons. The wiring may have disconnected or become damaged, or a disconnection could have happened further along in your electrical system. This might be the circuit breaker, fuse box or system switch. A knowledgeable technician can examine electrical connections and wiring until they locate the source of the problem.

e294 – Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring has to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not merely a software error. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start inspecting connectors.

They’ll detach the power and slowly check each wire, ensuring they are fully attached into the connector with the proper amount of bare copper. Once they find the malfunctioning connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can show up when the weather outside is particularly hot. The HVAC system can shut down and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will finally power down. Assuming the breakers are on, you can examine a handful of other places before calling a professional technician.

As this error can deplete your thermostat’s battery, the first step may be restoring enough power to figure out if this specific error code is what you’re dealing with. You can disconnect the thermostat from its base and provide power with a USB cable. Assuming it displays error code 195, you can continue to visually inspect components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to uncover anything wrong with these components, it will likely be best to get in touch with a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is receiving more power than necessary. This may stem from the breaker box, an error from the control board or thanks to a defective connection in the thermostat. Your technician should meticulously examine and test the Nest’s electrical system to figure out where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

Although this error code isn’t critical, it may still keep you from using the Nest thermostat like normal. Error code n260 refers to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from getting enough power. You can examine the Nest’s C connector for the presence of a C wire and adapt the wiring itself if there is. If not, you need a Nest Power Connector.

With installation of a Nest Power Connector, you might notice error code E297 show up. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead be required to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.

e104 – Critical

Similar to error code e103, e104 is a critical error originating from an overcurrent. If excess power is transported using the Nest’s wiring, it may damage internal components and can even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to protect from electrical damage, it’s suggested to switch the power off as soon as you can. You can then get in touch with a professional technician with the appropriate experience detecting and resolving electrical problems.

e73 – Critical

When your thermostat displays error code e73, it signifies that the Rc wire is not receiving power.

This may be as easy as the breaker being switched off, but it can also be a problem with the wiring. After switching off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure nothing is loose or damaged. If nothing seems to be out of place, it’s a good idea to speak with a local professional.