How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Operating a Nest thermostat is one of the best ways to improve the daily schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make changes. But as you can expect, it won’t work well or at all if you see an error code appear. The specific error code supplies useful information about the underlying problem, something a trained technician can use to provide solutions that much quicker.

Listed below are seven of the most frequent error codes you might encounter on your Nest thermostat. We’ll review the basics of each error code as well as how you can fix it and the projected cost to do so. Keep in mind that while the price will ultimately hinge on the exact Nest model, you can anticipate paying around $75-$200 for repairs. This should also cover travel and labor costs along with any specific parts needed to wrap up repairs.

e298 - Critical

This critical error code is limited to the latest models of the Nest thermostat and is displayed when the power is detached from the system. Since 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 problem is dealt with.

Losing power to your Nest thermostat can be for numerous reasons. The wiring may have disconnected or become damaged, or a disconnection may have occurred further along in the electrical system. This may be the circuit breaker, fuse box or system switch. A trained technician will examine 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 should be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to make sure it’s not just a software problem. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin looking at connectors.

They’ll disconnect the power and slowly look at each wire, making sure they are fully attached into the connector with the proper amount of uncovered copper. When they locate the problem connector, it can be exchanged for a new one.

e195 - Critical

This critical error code can surface when the weather outside is severely hot. The HVAC system can shut down and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will subsequently power down. In the event the breakers are on, you can check a few other places before calling a professional technician.

Because this error can deplete your thermostat’s battery, the first step may be supplying enough power to find out if this specific error code is what you’re dealing with. You can disconnect the thermostat from its base and provide power with a USB cable. In the event it displays error code 195, you may continue to visually check components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to find anything wrong with these components, it will likely be best to contact a pro.

e103 - Critical

Another critical error code, e103 signifies an electrical error with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is experiencing more power than needed. This may stem from the breaker box, an error from the control board or through a faulty connection in the thermostat. The technician can cautiously inspect 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 may 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 receiving sufficient 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.

With installation of a Nest Power Connector, you will sometimes notice error code E297 appear. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already 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 transported inside the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to take steps to prevent electrical damage, it’s recommended to switch the power off straightaway. You can then get a hold of a professional technician with the appropriate experience detecting and resolving 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 turned off, but it could also be an issue with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually check the wires to make sure they’re not loose or damaged. If nothing seems to be out of place, it’s best to contact a local professional.