Operating a Nest thermostat is one of the most convenient ways to perfect the everyday schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make adjustments. But as you might expect, it won’t work correctly or at all if you see an error code appear. The precise error code offers useful information about the underlying problem, something a professional technician can use to present solutions that much sooner.

Let’s consider seven of the most common error codes you may encounter on your Nest thermostat. We’ll review the basics of each error code as well as how you can solve it and the approximate cost to do so. Remember that while the price will ultimately hinge on the precise Nest model, you can count on paying about $75-$200 for repairs. This should include travel and labor costs as well as any specific components necessary to complete repairs.

e298 – Critical

This critical error code is limited to newer models of the Nest thermostat and appears when the power is shut off. Since this is a critical power error, the thermostat will swap to the backup battery system. The error message will continue to be displayed until the issue is dealt with.

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

e294 – Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring needs 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 make sure it’s not just a software issue. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin checking connectors.

They’ll shut off the power and progressively inspect each wire, making sure they are fully placed 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 appear when the weather outside is severely hot. The HVAC system can fail and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will eventually turn off. Presuming the breakers are on, you can examine a few other places before contacting a professional technician.

Since this error can deplete your thermostat’s battery, the first step may be providing enough power to find out if this specific error code is what you’re working with. You can disconnect the thermostat from its base and supply power with a USB cable. Assuming it presents error code 195, you should continue to visually check components such as 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 suggests an electrical problem with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is receiving more power than what is safe and normal. This can stem from the breaker box, an error from the control board or thanks to a faulty connection in the thermostat. The technician can meticulously investigate 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

Even though this error code isn’t critical, it can still keep 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 obtaining adequate power. You can examine the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you need a Nest Power Connector.

During installation of a Nest Power Connector, you may notice error code E297 be displayed. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been 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 that’s the result of an overcurrent. If excess power is being delivered inside the Nest’s wiring, it may 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 switch the power off straightaway. You can then contact a professional technician with the necessary experience diagnosing and solving electrical malfunctions.

e73 – Critical

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

This may be as straightforward as the breaker being switched off, but it could also be something with the wiring. After turning off the power to your HVAC system and thermostat, you can visually check the wires to make sure none of them are loose or damaged. If nothing appears to be out of place, it’s a good idea to get in touch with a local professional.