Installing a Nest thermostat is one of the best ways to improve the daily schedule of your heating and cooling. This smart thermostat can recognize your preferences and automatically make changes. But as you may expect, it won’t work properly or at all if you see an error code show up. The precise error code provides useful information about the root of the problem, something a professional technician can use to offer solutions that much faster.
Here are seven of the most frequent error codes you could find on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you could solve it and the projected cost to do so. Keep in mind that while the price will ultimately be dependent on the exact Nest model, you can anticipate paying around $75-$200 for repairs. This should include travel and labor costs on top of any specific components needed to wrap up repairs.
e298 - Critical
This critical error code is limited to new models of the Nest thermostat and is displayed 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 continue to be displayed until the issue is dealt with.
Losing power to your Nest thermostat can be for numerous reasons. The wiring might have disconnected or become damaged, or a disconnection could have appeared further along in the electrical system. This could be the circuit breaker, fuse box or system switch. A certified technician can inspect electrical connections and wiring until they uncover the source of the problem.
e294 - Critical
Critical error code e294 appears when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to make sure it’s not just a software problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin inspecting connectors.
They’ll detach the power and progressively check each wire, making sure they are fully inserted into the connector with the proper amount of exposed copper. When they pinpoint the malfunctioning 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 fail and stop sending power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will subsequently power down. Assuming the breakers are on, you can check a couple of other places before calling a professional technician.
Because this error can drain 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 disconnect the thermostat from its base and deliver power by using a USB cable. In the event it reveals error code 195, you should continue to visually inspect components such as the wiring as well as your air conditioner’s air filter or drainage system. If you can't detect anything wrong with these components, it's maybe 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 receiving more power than what is safe and normal. This may stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. A technician should cautiously inspect and test the Nest’s electrical system to determine where the power is surging or why the thermostat believes there’s an overcurrent problem.
Even though this error code isn’t critical, it might still prevent you from using the Nest thermostat like normal. Error code n260 concerns the lack of a C wire or Nest Power Connector, as not having 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 adjust the wiring itself if there is. If not, you need a Nest Power Connector.
With installation of a Nest Power Connector, you might notice error code E297 be displayed. This can be remedied 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 stemming from an overcurrent. If too much power is sent using the Nest’s wiring, it could 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 a good idea to turn the power off as soon as possible. You can then get a hold of a professional technician with the appropriate experience diagnosing and fixing electrical issues.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not receiving power. This could be as straightforward as the breaker being shut off, but it may also be an issue with the wiring. After shutting 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 looks to be out of place, it’s best to contact a local professional.