How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Using a Nest thermostat is one of the easiest ways to improve the everyday schedule of your heating and cooling. This smart thermostat can learn your preferences and automatically make improvements. But as you may expect, it won’t work properly or at all if you see an error code show up. The exact error code offers useful information about the underlying problem, something a trained technician can use to offer solutions that much faster.

Listed below are seven of the most frequent error codes you could encounter on your Nest thermostat. We’ll explain the basics of each error code on top of how you could solve it and the projected cost to do so. Remember that while the price will ultimately be dependent on the precise Nest model, you can anticipate paying around $75-$200 for repairs. This should also cover travel and labor costs along with any specific hardware required to wrap up repairs.

e298 - Critical

This critical error code is limited to new models of the Nest thermostat and appears when the power is detached from the system. 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 several reasons. The wiring could have disconnected or become damaged, or a disconnection might have happened further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A knowledgeable technician should check 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 has to be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to make sure it’s not merely a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start looking at connectors.

They’ll detach the power and slowly inspect each wire, seeing to it that they are fully placed into the connector with the proper amount of bare copper. After they pinpoint the damaged connector, it can be swapped for a new one.

e195 - Critical

This critical error code can show up when the weather outside is severely hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will subsequently shut down. Presuming 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 could be restoring enough power to determine if this specific error code is what you’re facing. You can separate the thermostat from its base and provide power by using a USB cable. Assuming it presents error code 195, you should continue to visually check 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 probably be best to get in touch with a pro.

e103 - Critical

Another critical error code, e103 signifies an electrical problem with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is receiving more power than needed. This may stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. A technician should carefully examine 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 can still keep you from using the Nest thermostat how you want to. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from obtaining adequate power. You can check the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you can get a Nest Power Connector.

Due to installation of a Nest Power Connector, you might notice error code E297 show up. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been 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 too much power is being delivered inside the Nest’s wiring, it can damage internal components and could even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to take steps to prevent electrical damage, it’s recommended to shut the power off as soon as possible. You can then get in touch with a professional technician with the appropriate experience detecting and fixing electrical issues.

e73 - Critical

When your thermostat displays error code e73, it indicates that the Rc wire is not getting power. This will sometimes be as straightforward as the breaker being turned off, but it may also be a problem with the wiring. After turning off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure they’re not loose or damaged. If nothing looks to be out of place, it’s time to speak with a local professional.