Installing a Nest thermostat is one of the best ways to improve the daily schedule of your comfort system. 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 root of the problem, something a knowledgeable technician can use to provide solutions that much sooner.
Here are seven of the most frequent error codes you may find on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you could address it and the projected cost to do so. Don't forget that while the costs will ultimately hinge on the precise Nest model, you can expect to pay around $75-$200 for repairs. This should also cover travel and labor costs along with any specific components needed to finish repairs.
e298 - Critical
This critical error code is limited to new models of the Nest thermostat and is displayed when the power is disconnected from the system. Since 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 fixed.
Losing power to your Nest thermostat can be for a number of reasons. The wiring could have disconnected or become damaged, or a disconnection might have occurred further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician should check electrical connections and wiring until they find the source of the problem.
e294 - Critical
Critical error code e294 is displayed 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 merely a software problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start looking at connectors.
They’ll detach the power and gradually inspect each wire, making sure they are fully placed into the connector with the correct amount of exposed copper. Once they pinpoint the problem connector, it can be replaced for a new one.
e195 - Critical
This critical error code can show up when the weather outside is particularly hot. The HVAC system can shut down and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will eventually turn off. Assuming the breakers are on, you can check a handful of other places before consulting a professional technician.
Since this error can drain your thermostat’s battery, the first step may be providing enough power to find out if this specific error code is what you’re facing. You can disconnect the thermostat from its base and supply power with a USB cable. Assuming it reveals error code 195, you may continue to visually check components such as 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 call 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 experiencing more power than needed. This will sometimes stem from the breaker box, an error from the control board or through a defective connection in the thermostat. A technician can 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.
While this error code isn’t critical, it may still prevent 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 missing 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 adjust the wiring itself if there is. If not, you’ll need a Nest Power Connector.
With installation of a Nest Power Connector, you might notice error code E297 be displayed. 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
Like error code e103, e104 is a critical error originating from an overcurrent. If too much power is transported through the Nest’s wiring, it may damage internal components and can even be a fire hazard. If you notice this error code pop up on your Nest thermostat and want to take steps to prevent electrical damage, it’s suggested to switch the power off as soon as possible. You can then get a hold of a professional technician with the necessary experience diagnosing and solving electrical malfunctions.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not getting power. This may be as straightforward as the breaker being shut off, but it may also be something with the wiring. After switching 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 appears to be out of place, it’s best to get in touch with a local professional.