How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Installing a Nest thermostat is one of the best ways to perfect the daily schedule of your heating and cooling. This smart thermostat can recognize your preferences and automatically make changes. But as you can expect, it won’t work correctly or at all if you see an error code show up. The precise error code offers useful information about the underlying problem, something a professional technician can use to offer solutions that much faster.

Let's consider seven of the most likely error codes you could find 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 price will ultimately depend 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 required to complete repairs.

e298 - Critical

This critical error code is limited to new models of the Nest thermostat and shows up when the power is detached from the system. As this is a critical power error, the thermostat will swap to the backup battery system. The error message will remain on display until the problem is dealt with.

Losing power to your Nest thermostat can be for several reasons. The wiring might have disconnected or become damaged, or a disconnection may have happened further along in your home's electrical system. This could be the circuit breaker, fuse box or system switch. A trained technician can examine electrical connections and wiring until they locate 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 make sure it’s not simply a software error. 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, seeing to it that they are fully attached into the connector with the proper amount of uncovered copper. Once they locate the damaged connector, it can be exchanged for a new one.

e195 - Critical

This critical error code can show up when the weather outside is severely 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 eventually shut down. Presuming the breakers are on, you can search a few other places before calling a professional technician.

As this error can deplete your thermostat’s battery, the first step could be restoring enough power to figure out if this specific error code is what you’re working with. You can separate the thermostat from its base and supply power by using a USB cable. If it displays 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 can't 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 suggests an electrical issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is getting 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 will meticulously examine and test the Nest’s electrical system to figure out where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

Although this error code isn’t critical, it might still keep you from using the Nest thermostat like normal. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from obtaining sufficient 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’ll need a Nest Power Connector.

During installation of a Nest Power Connector, you may notice error code E297 show up. 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

Similar to error code e103, e104 is a critical error that's the result of an overcurrent. If too much power is transported using the Nest’s wiring, it may damage internal components and could 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 recommended to shut the power off straightaway. You can then contact a professional technician with the appropriate experience detecting and fixing 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 straightforward as the breaker being switched off, but it could also be a problem with the wiring. After shutting 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 looks to be out of place, it’s a good idea to contact a local professional.