How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Using a Nest thermostat is one of the best ways to optimize the day-to-day schedule of your heating and cooling. This smart thermostat can recognize your preferences and automatically make improvements. But as you may expect, it won’t work properly or at all if you see an error code appear. The specific error code offers useful information about the underlying problem, something a knowledgeable technician can use to provide solutions that much sooner.

Listed below are seven of the most frequent error codes you might encounter on your Nest thermostat. We’ll explain the basics of each error code as well as how you could address it and the projected cost to do so. Remember that while the costs will ultimately depend on the specific 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 parts necessary to complete repairs.

e298 - Critical

This critical error code is limited to new models of the Nest thermostat and is displayed when the power is shut off. Because this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on display until the problem is resolved.

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

e294 - Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring should be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to ensure it’s not merely a software issue. 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 inspect each wire, ensuring they are fully attached into the connector with the correct amount of uncovered copper. When they find the malfunctioning connector, it can be exchanged for a new one.

e195 - Critical

This critical error code can surface when the weather outside is especially hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will finally shut down. In the event the breakers are on, you can inspect a few other places before consulting a professional technician.

Because this error can drain your thermostat’s battery, the first step could 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 deliver power through a USB cable. If it displays error code 195, you can continue to visually inspect components like the wiring as well as your air conditioner’s air filter or drainage system. If you can't detect anything wrong with these components, it will likely be best to contact a pro.

e103 - Critical

Another critical error code, e103 signifies an electrical problem with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is receiving 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 bad connection in the thermostat. Your technician needs to cautiously examine 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 can still prevent you from using the Nest thermostat how you want 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 check the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you can get a Nest Power Connector.

With 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 be required 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 stemming from an overcurrent. If too much power is transported inside the Nest’s wiring, it can damage internal components and can even be a fire hazard. If you see this error code appear on your Nest thermostat and want to guard against electrical damage, it’s a good idea to shut the power off straightaway. You can then get a hold of a professional technician with the proper experience detecting 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 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 nothing is loose or damaged. If nothing looks to be out of place, it’s a good idea to contact a local professional.