How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Operating a Nest thermostat is one of the most convenient ways to optimize the everyday schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make changes. But as you might expect, it won’t work well or at all if you see an error code on the display. The exact error code provides useful information about the root of the problem, something a trained technician can use to offer solutions that much quicker.

Here are seven of the most likely error codes you may encounter on your Nest thermostat. We’ll explain the basics of each error code as well as how you can address it and the projected cost to do so. Don't forget that while the price will ultimately depend on the precise Nest model, you can anticipate paying about $75-$200 for repairs. This should also cover travel and labor costs as well as any specific parts required 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. Since this is a critical power error, the thermostat will switch to the backup battery system. The error message will continue to be displayed until the problem is resolved.

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

e294 - Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring has to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to ensure it’s not just a software error. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start inspecting connectors.

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

e195 - Critical

This critical error code can appear when the weather outside is severely hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will finally turn off. Assuming the breakers are on, you can examine a few other places before calling a professional technician.

Because this error can drain your thermostat’s battery, the first step might 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 supply power with a USB cable. In the event it reveals error code 195, you can continue to visually examine components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to uncover anything wrong with these components, it will probably be best to get in touch with a pro.

e103 - Critical

Another critical error code, e103 indicates an electrical issue 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 bad connection in the thermostat. Your technician needs to cautiously inspect and test the Nest’s electrical system to determine where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

Although this error code isn’t critical, it could still stop you from using the Nest thermostat how you prefer to. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from obtaining enough power. You can check the Nest’s C connector for the presence of a C wire and adapt the wiring itself if there is. If not, you can get a Nest Power Connector.

With installation of a Nest Power Connector, you will sometimes notice error code E297 be displayed. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead be required 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 originating from an overcurrent. If excess power is transported using the Nest’s wiring, it may damage internal components and can even be a fire hazard. If you see this error code appear on your Nest thermostat and want to protect from electrical damage, it’s recommended to shut the power off as soon as you can. You can then get a hold of a professional technician with the necessary experience identifying and solving electrical issues.

e73 - Critical

When your thermostat displays error code e73, it signifies that the Rc wire is not receiving power. This may 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 inspect the wires to make sure nothing is loose or damaged. If nothing appears to be out of place, it’s best to get in touch with a local professional.