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

Listed below are seven of the most common error codes you might discover on your Nest thermostat. We’ll walk you through the basics of each error code along with how you might address it and the projected cost to do so. Keep in mind that while the costs will ultimately be dependent on the precise Nest model, you can count on paying between $75-$200 for repairs. This should include things like travel and labor costs as well as any specific components necessary to finish repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and shows up when the power is disconnected from the system. As this is a critical power error, the thermostat will swap to the backup battery system. The error message will remain on the screen until the issue is resolved.

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

e294 – Critical

Critical error code e294 appears when your Nest thermostat’s wiring should be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first complete a factory reset of your thermostat to make sure it’s not simply 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 gradually inspect each wire, making sure they are fully inserted into the connector with the correct amount of uncovered copper. After they find the problem connector, it can be replaced for a new one.

e195 – Critical

This critical error code can appear when the weather outside is particularly hot. The HVAC system can fail and stop giving power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will subsequently turn off. Assuming the breakers are on, you can check a couple of other places before consulting a professional technician.

As this error can deplete your thermostat’s battery, the first step may be supplying enough power to determine if this specific error code is what you’re facing. You can separate the thermostat from its base and supply power by using a USB cable. In the event 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 can’t find anything wrong with these components, it will probably be best to call a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is experiencing more power than what is safe and normal. This will sometimes stem from the breaker box, an error from the control board or through a defective connection in the thermostat. A technician can carefully inspect and test the Nest’s electrical system to determine where the power is surging or why the thermostat is convinced 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 the absence of one can block your Nest from obtaining enough power. You can inspect the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you need a Nest Power Connector.

During installation of a Nest Power Connector, you might 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

Like error code e103, e104 is a critical error that’s the result of an overcurrent. If too much power is transported inside the Nest’s wiring, it could damage internal components and may even be a fire hazard. If you see this error code pop up 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 get a hold of a professional technician with the proper experience identifying and resolving 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 turned off, but it could also be a problem with the wiring. After turning off the power to your HVAC system and thermostat, you can visually examine the wires to make sure they’re not loose or damaged. If nothing appears to be out of place, it’s a good idea to speak with a local professional.