How to Resolve These Seven Error Codes on Your Nest Thermostat

Operating a Nest thermostat is one of the best ways to optimize the everyday schedule of your HVAC system. This smart thermostat can learn your preferences and automatically make adjustments. But as you may expect, it won’t work correctly or at all if you see an error code on the display. The exact error code offers useful information about the source of the problem, something a knowledgeable technician can use to provide solutions that much quicker.

Let’s consider seven of the most likely error codes you could encounter on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you can address it and the estimated cost to do so. Don’t forget that while the investment will ultimately depend on the specific Nest model, you can anticipate paying about $75-$200 for repairs. This should include things like travel and labor costs on top of any specific parts needed to complete repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and shows up when the power is shut off. 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 problem is resolved.

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

e294 – Critical

Critical error code e294 appears 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 make sure it’s not just a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start looking at connectors.

They’ll disconnect the power and progressively inspect each wire, seeing to it that they are fully inserted into the connector with the proper amount of uncovered copper. When they locate the malfunctioning connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can show up when the weather outside is especially hot. The HVAC system can shut down and stop sending power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will finally power down. Assuming the breakers are on, you can inspect a handful of other places before contacting a professional technician.

Because this error can drain your thermostat’s battery, the first step might 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 supply power through a USB cable. Assuming it presents error code 195, you may continue to visually inspect components including the wiring as well as your air conditioner’s air filter or drainage system. If you don’t uncover 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 can refer to an overcurrent problem, which means the wiring is experiencing more power than necessary. This may stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. Your technician needs to carefully investigate and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

While this error code isn’t critical, it might still prevent you from using the Nest thermostat like normal. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from getting sufficient power. You can check the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you’ll need a Nest Power Connector.

During 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 was already installed, you’ll instead have 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 stemming from an overcurrent. If excess power is transported through the Nest’s wiring, it could 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 take steps to prevent electrical damage, it’s recommended to turn the power off straightaway. You can then contact a professional technician with the appropriate experience identifying and resolving electrical problems.

e73 – Critical

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

This might be as easy as the breaker being shut off, but it can also be something 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 seems to be out of place, it’s time to contact a local professional.