Using a Nest thermostat is one of the most convenient ways to improve the day-to-day schedule of your HVAC system. This smart thermostat can be taught your preferences and automatically make changes. But as you can expect, it won’t work properly or at all if you see an error code on the display. The specific error code provides useful information about the source of the problem, something a professional technician can use to provide solutions that much sooner.

Here are seven of the most likely error codes you might discover on your Nest thermostat. We’ll explain the basics of each error code on top of how you can fix it and the estimated cost to do so. Don’t forget that while the investment will ultimately hinge on the exact Nest model, you can count on paying around $75-$200 for repairs. This should include things like travel and labor costs as well as any specific components required to finish 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 the screen until the issue is fixed.

Losing power to your Nest thermostat can be for several reasons. The wiring could have disconnected or become damaged, or a disconnection may have appeared further along in your home’s electrical system. This might be the circuit breaker, fuse box or system switch. A professional technician can check 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 will need to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not merely a software problem. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start checking connectors.

They’ll shut off the power and progressively check each wire, ensuring they are fully placed into the connector with the proper amount of uncovered copper. When they pinpoint 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 giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will eventually power down. In the event the breakers are on, you can inspect a handful of other places before contacting a professional technician.

Since 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 working with. You can detach the thermostat from its base and deliver power through a USB cable. Assuming it displays error code 195, you can continue to visually examine components including the wiring as well as your air conditioner’s air filter or drainage system. If you can’t uncover anything wrong with these components, it’s maybe best to contact a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical error with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is getting more power than what is safe and normal. This can stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. The technician will carefully investigate 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

Even though this error code isn’t critical, it might still prevent you from using the Nest thermostat how you prefer to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as not having 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 modify the wiring itself if there is. If not, you’ll need a Nest Power Connector.

With installation of a Nest Power Connector, you might notice error code E297 show up. This can be dealt with 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 excessive power is sent through the Nest’s wiring, it may 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 you can. You can then get in touch with a professional technician with the appropriate experience detecting and fixing electrical damage.

e73 – Critical

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

This may be as straightforward as the breaker being switched off, but it may 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 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.