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 day-to-day schedule of your HVAC system. This smart thermostat can learn your preferences and automatically make changes. But as you might expect, it won’t work correctly or at all if you see an error code show up. The specific error code offers useful information about the source of the problem, something a knowledgeable technician can use to offer solutions that much sooner.

Here are seven of the most frequent error codes you may discover on your Nest thermostat. We’ll walk you through the basics of each error code along with how you can address it and the approximate cost to do so. Remember that while the price will ultimately be dependent on the exact Nest model, you can count on paying between $75-$200 for repairs. This should also cover travel and labor costs along with any specific hardware necessary to finish 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 continue to be displayed until the issue 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 could have occurred further along in your electrical system. This might be the circuit breaker, fuse box or system switch. A trained technician should check electrical connections and wiring until they locate the root of the problem.

e294 - Critical

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

They’ll disconnect the power and progressively check each wire, ensuring they are fully inserted into the connector with the correct amount of uncovered copper. After they pinpoint the damaged connector, it can be exchanged for a new one.

e195 - Critical

This critical error code can surface when the weather outside is particularly hot. The HVAC system can shut down and stop sending power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will finally turn off. Assuming the breakers are on, you can examine a couple of other places before calling a professional technician.

Because this error can deplete your thermostat’s battery, the first step could be providing enough power to determine if this specific error code is what you’re facing. You can separate the thermostat from its base and deliver power through a USB cable. In the event it presents 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 don’t find anything wrong with these components, it will likely be best to get in touch with a pro.

e103 - Critical

Another critical error code, e103 suggests an electrical error with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is getting more power than needed. This may stem from the breaker box, an error from the control board or thanks to a defective connection in the thermostat. Your technician will meticulously investigate and test the Nest’s electrical system to understand 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 prevent you from using the Nest thermostat how you prefer to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining adequate power. You can inspect the Nest’s C connector for the presence of a C wire and adapt 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 remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead need 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 stemming from an overcurrent. If excess power is transported inside the Nest’s wiring, it can damage internal components and may 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 recommended to switch the power off straightaway. You can then contact a professional technician with the necessary experience detecting and solving electrical damage.

e73 - Critical

When your thermostat displays error code e73, it indicates that the Rc wire is not receiving power. This will sometimes be as straightforward as the breaker being turned off, but it could also be an issue with the wiring. After turning off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure none of them are loose or damaged. If nothing seems to be out of place, it’s a good idea to speak with a local professional.

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