Operating a Nest thermostat is one of the most convenient ways to optimize the daily schedule of your heating and cooling. This smart thermostat can recognize your preferences and automatically make improvements. But as you might expect, it won’t work properly or at all if you see an error code show up. The exact error code supplies useful information about the root of the problem, something a trained technician can use to provide solutions that much sooner.

Let’s consider seven of the most frequent error codes you might find on your Nest thermostat. We’ll walk you through the basics of each error code along with how you could address it and the projected cost to do so. Keep in mind that while the costs will ultimately be dependent on the exact Nest model, you can anticipate paying between $75-$200 for repairs. This should include things like travel and labor costs along with any specific hardware necessary to complete repairs.

e298 – Critical

This critical error code is limited to newer models of the Nest thermostat and shows up when the power is shut off. Since this is a critical power error, the thermostat will swap to the backup battery system. The error message will remain on display until the issue is resolved.

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

e294 – Critical

Critical error code e294 shows up when your Nest thermostat’s wiring should be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first complete 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 start inspecting connectors.

They’ll disconnect the power and slowly check each wire, seeing to it that they are fully inserted into the connector with the proper amount of exposed copper. When they find the damaged connector, it can be replaced for a new one.

e195 – Critical

This critical error code can appear when the weather outside is especially hot. The HVAC system can fail and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will eventually power down. In the event the breakers are on, you can examine a few other places before consulting a professional technician.

Because this error can drain your thermostat’s battery, the first step may be providing enough power to determine if this specific error code is what you’re working with. You can disconnect the thermostat from its base and deliver power with a USB cable. If it displays error code 195, you may continue to visually examine components such as 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 likely be 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 experiencing more power than what is safe and normal. This will sometimes stem from the breaker box, an error from the control board or thanks to a defective connection in the thermostat. A technician will carefully investigate 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 stop you from using the Nest thermostat like normal. Error code n260 refers to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from obtaining sufficient 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.

Due to 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 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 too much power is being delivered through the Nest’s wiring, it can damage internal components and could even be a fire hazard. If you see this error code show up on your Nest thermostat and want to protect from electrical damage, it’s suggested to shut the power off as soon as you can. You can then get in touch with a professional technician with the proper experience identifying and fixing electrical malfunctions.

e73 – Critical

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

This might be as straightforward as the breaker being turned off, but it could also be an issue with the wiring. After switching 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 seems to be out of place, it’s best to get in touch with a local professional.