Using a Nest thermostat is one of the most convenient ways to perfect the day-to-day schedule of your heating and cooling. This smart thermostat can learn your preferences and automatically make changes. But as you might expect, it won’t work correctly or at all if you see an error code appear. The precise error code offers useful information about the underlying problem, something a knowledgeable technician can use to present solutions that much faster.
Here are seven of the most likely error codes you could find on your Nest thermostat. We’ll explain the basics of each error code on top of how you might fix it and the estimated cost to do so. Keep in mind that while the price will ultimately hinge on the exact Nest model, you can count on paying around $75-$200 for repairs. This should also cover travel and labor costs along with any specific parts necessary to complete repairs.
e298 - Critical
This critical error code is limited to new models of the Nest thermostat and appears when the power is shut off. 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 resolved.
Losing power to your Nest thermostat can be for several reasons. The wiring may have disconnected or become damaged, or a disconnection may have appeared further along in your home's electrical system. This could be the circuit breaker, fuse box or system switch. A knowledgeable technician should examine electrical connections and wiring until they uncover the source of the problem.
e294 - Critical
Critical error code e294 is displayed 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 simply a software problem. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin inspecting connectors.
They’ll shut off the power and gradually check each wire, ensuring they are fully attached into the connector with the proper amount of uncovered copper. After they pinpoint the damaged connector, it can be exchanged for a new one.
e195 - Critical
This critical error code can appear when the weather outside is particularly hot. The HVAC system can shut down and stop giving power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will eventually power down. In the event the breakers are on, you can inspect a few other places before contacting a professional technician.
As this error can deplete your thermostat’s battery, the first step could be supplying enough power to figure out if this specific error code is what you’re facing. You can detach the thermostat from its base and supply power through a USB cable. In the event it displays error code 195, you may continue to visually examine components such as 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 likely be best to call a pro.
e103 - Critical
Another critical error code, e103 indicates an electrical malfunction with your Nest thermostat. More specifically, e103 will 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 through a faulty connection in the thermostat. A technician will cautiously examine and test the Nest’s electrical system to understand where the power is surging or why the thermostat is convinced there’s an overcurrent problem.
Even though this error code isn’t critical, it can still prevent you from using the Nest thermostat how you want to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from getting adequate power. You can inspect the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you’ll need 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 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 that's the result of an overcurrent. If too much power is being delivered through the Nest’s wiring, it can damage internal components and may 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 contact a professional technician with the proper experience detecting and fixing electrical damage.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not getting power. This will sometimes be as simple as the breaker being turned off, but it can also be an issue 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 seems to be out of place, it’s time to speak with a local professional.