Using a Nest thermostat is one of the easiest ways to improve the daily schedule of your HVAC system. This smart thermostat can recognize your preferences and automatically make changes. But as you may expect, it won’t work properly or at all if you see an error code appear. The exact error code provides useful information about the source of the problem, something a professional technician can use to present solutions that much faster.

Listed below are seven of the most frequent error codes you might discover on your Nest thermostat. We’ll explain the basics of each error code as well as how you might fix it and the estimated cost to do so. Don’t forget that while the investment will ultimately hinge on the precise Nest model, you can expect to pay about $75-$200 for repairs. This should also cover travel and labor costs as well as any specific parts necessary to finish repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and is displayed when the power is detached from the system. Because this is a critical power error, the thermostat will change to the backup battery system. The error message will continue to be displayed until the problem is fixed.

Losing power to your Nest thermostat can be for several reasons. The wiring might have disconnected or become damaged, or a disconnection could have appeared further along in the electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician can inspect 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 needs to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first complete a factory reset of your thermostat to make sure it’s not merely a software error. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin checking connectors.

They’ll shut off the power and slowly inspect each wire, ensuring they are fully attached into the connector with the correct amount of bare copper. Once they find the problem connector, it can be replaced for a new one.

e195 – Critical

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

Since this error can consume your thermostat’s battery, the first step could be supplying enough power to figure out if this specific error code is what you’re dealing with. You can separate the thermostat from its base and provide power by using a USB cable. Assuming it displays error code 195, you can continue to visually inspect components like 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 call a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical malfunction with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is receiving more power than necessary. This will sometimes stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. A technician should carefully examine and test the Nest’s electrical system to understand where the power is surging or why the thermostat is convinced there’s an overcurrent problem.

n260

Although this error code isn’t critical, it might still keep you from using the Nest thermostat how you want to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from receiving sufficient 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 can get a Nest Power Connector.

Due to installation of a Nest Power Connector, you might notice error code E297 show up. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead have 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 too much power is sent inside the Nest’s wiring, it may damage internal components and may even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to guard against electrical damage, it’s a good idea to turn the power off straightaway. You can then contact a professional technician with the proper experience identifying and resolving electrical issues.

e73 – Critical

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

This might be as simple as the breaker being shut off, but it can also be something 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 appears to be out of place, it’s a good idea to speak with a local professional.