Using a Nest thermostat is one of the easiest ways to optimize the everyday schedule of your HVAC system. This smart thermostat can learn your preferences and automatically make changes. But as you may expect, it won’t work well 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 frequent error codes you could find on your Nest thermostat. We’ll explain the basics of each error code as well as how you could solve it and the approximate cost to do so. Keep in mind that while the investment will ultimately depend on the exact Nest model, you can anticipate paying around $75-$200 for repairs. This should also cover travel and labor costs as well as any specific components required 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 disconnected from the system. Because 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 numerous reasons. The wiring could have disconnected or become damaged, or a disconnection may have occurred further along in the electrical system. This could be the circuit breaker, fuse box or system switch. A certified technician will check electrical connections and wiring until they locate the source of the problem.

e294 – Critical

Critical error code e294 shows up when your Nest thermostat’s wiring should be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to make sure it’s not just a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin inspecting connectors.

They’ll detach the power and progressively check each wire, making sure they are fully attached into the connector with the correct amount of exposed copper. When they find the problem connector, it can be replaced for a new one.

e195 – Critical

This critical error code can show up when the weather outside is especially hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will finally shut down. Presuming the breakers are on, you can examine a couple of other places before consulting a professional technician.

As this error can consume your thermostat’s battery, the first step might be restoring enough power to determine if this specific error code is what you’re facing. You can separate the thermostat from its base and provide power by using a USB cable. Assuming it reveals error code 195, you should continue to visually inspect components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to detect anything wrong with these components, it will probably be best to get in touch with a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical problem with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is getting more power than needed. This will sometimes stem from the breaker box, an error from the control board or thanks to a defective connection in the thermostat. The technician should cautiously inspect and test the Nest’s electrical system to determine where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

Although this error code isn’t critical, it may still stop you from using the Nest thermostat how you prefer to. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from receiving sufficient power. You can inspect the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you can get a Nest Power Connector.

Due to installation of a Nest Power Connector, you may notice error code E297 appear. This can be dealt with 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 that’s the result of an overcurrent. If excessive power is transported through the Nest’s wiring, it can damage internal components and can even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to protect from electrical damage, it’s suggested to turn the power off straightaway. You can then get a hold of a professional technician with the appropriate experience identifying and resolving electrical damage.

e73 – Critical

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

This will sometimes 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 check the wires to make sure none of them are loose or damaged. If nothing looks to be out of place, it’s a good idea to get in touch with a local professional.