Using a Nest thermostat is one of the most convenient ways to improve the daily schedule of your heating and cooling. This smart thermostat can learn 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 on the display. The exact error code offers useful information about the root of the problem, something a knowledgeable technician can use to present solutions that much faster.

Listed below are seven of the most common error codes you may discover on your Nest thermostat. We’ll explain the basics of each error code along with how you might solve it and the estimated cost to do so. Keep in mind that while the costs will ultimately hinge on the precise Nest model, you can count on paying about $75-$200 for repairs. This should include things like travel and labor costs on top of any specific hardware required 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. As this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on the screen until the problem is fixed.

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

e294 – Critical

Critical error code e294 shows up when your Nest thermostat’s wiring has to be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first perform a factory reset of your thermostat to make sure it’s not just a software problem. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start looking at connectors.

They’ll detach the power and progressively inspect each wire, making sure they are fully inserted into the connector with the proper amount of exposed copper. Once they pinpoint the damaged connector, it can be replaced for a new one.

e195 – Critical

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

As this error can drain your thermostat’s battery, the first step might be providing enough power to find out if this specific error code is what you’re dealing with. You can separate the thermostat from its base and deliver power by using a USB cable. In the event it reveals error code 195, you may continue to visually inspect components such as the wiring as well as your air conditioner’s air filter or drainage system. If you don’t detect anything wrong with these components, it will likely be best to contact a pro.

e103 – Critical

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

n260

While this error code isn’t critical, it could still stop you from using the Nest thermostat like normal. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from receiving enough power. You can check the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you can get a Nest Power Connector.

With installation of a Nest Power Connector, you will sometimes 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 need 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 excessive power is transported using the Nest’s wiring, it can damage internal components and could even be a fire hazard. If you see this error code appear on your Nest thermostat and want to protect from electrical damage, it’s recommended to turn the power off as soon as possible. You can then get in touch with a professional technician with the appropriate experience detecting and solving electrical malfunctions.

e73 – Critical

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

This could be as easy as the breaker being shut off, but it could also be something with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure they’re not loose or damaged. If nothing appears to be out of place, it’s time to contact a local professional.