Operating a Nest thermostat is one of the most convenient ways to perfect the daily schedule of your comfort system. 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 provides useful information about the source of the problem, something a trained technician can use to provide solutions that much faster.

Here are seven of the most likely error codes you might discover on your Nest thermostat. We’ll walk you through the basics of each error code along with how you can fix it and the projected cost to do so. Don’t forget that while the price will ultimately be dependent on the precise Nest model, you can count on paying between $75-$200 for repairs. This should include travel and labor costs on top of any specific hardware needed to wrap up repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and is displayed when the power is detached from the system. As 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 several reasons. The wiring could have disconnected or become damaged, or a disconnection could have happened further along in your home’s electrical system. This may be the circuit breaker, fuse box or system switch. A professional technician will examine electrical connections and wiring until they find the root 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 should reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not just a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin looking at connectors.

They’ll shut off the power and slowly inspect each wire, making sure they are fully attached into the connector with the proper amount of uncovered copper. Once they locate the malfunctioning connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can appear when the weather outside is particularly hot. The HVAC system can break down and stop sending power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will eventually turn off. Presuming the breakers are on, you can search a handful of other places before contacting a professional technician.

Because this error can deplete your thermostat’s battery, the first step might be providing enough power to figure out if this specific error code is what you’re working with. You can disconnect the thermostat from its base and supply power through a USB cable. In the event it reveals error code 195, you can continue to visually check 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’s maybe best to contact a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical error with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is getting more power than needed. This may stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. The technician will carefully examine and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

Although this error code isn’t critical, it could still prevent you from using the Nest thermostat how you want to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining adequate 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 may notice error code E297 appear. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been installed, you’ll instead have to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.

e104 – Critical

Just like error code e103, e104 is a critical error originating from an overcurrent. If excessive power is sent through the Nest’s wiring, it can damage internal components and may 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 a hold of a professional technician with the proper experience diagnosing and solving electrical problems.

e73 – Critical

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

This might be as easy as the breaker being turned off, but it may also be a problem with the wiring. After shutting 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.