Installing a Nest thermostat is one of the best ways to perfect the everyday schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make changes. But as you might expect, it won’t work well or at all if you see an error code show up. The specific error code supplies useful information about the underlying problem, something a professional technician can use to present solutions that much faster.
Listed below 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 estimated cost to do so. Don't forget that while the costs will ultimately depend on the precise Nest model, you can expect to pay between $75-$200 for repairs. This should include things like travel and labor costs on top of any specific parts necessary to finish repairs.
e298 - Critical
This critical error code is limited to new models of the Nest thermostat and shows up when the power is shut off. 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 numerous reasons. The wiring might have disconnected or become damaged, or a disconnection could have appeared further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A trained technician should examine electrical connections and wiring until they find the root of the problem.
e294 - Critical
Critical error code e294 appears when your Nest thermostat’s wiring should 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 ensure it’s not just a software problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start inspecting connectors.
They’ll shut off the power and gradually inspect each wire, seeing to it that they are fully attached into the connector with the proper amount of uncovered copper. After they find the malfunctioning connector, it can be replaced for a new one.
e195 - Critical
This critical error code can appear when the weather outside is severely hot. The HVAC system can shut down and stop giving power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will eventually shut down. Assuming the breakers are on, you can search a couple of other places before contacting a professional technician.
As this error can deplete your thermostat’s battery, the first step might be providing enough power to find out if this specific error code is what you’re dealing with. You can detach the thermostat from its base and deliver power with a USB cable. If it presents error code 195, you can continue to visually inspect components like the wiring as well as your air conditioner’s air filter or drainage system. If you don’t detect anything wrong with these components, it will likely be best to call a pro.
e103 - Critical
Another critical error code, e103 suggests an electrical malfunction with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is experiencing 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. The technician needs to carefully examine and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes there’s an overcurrent problem.
Although this error code isn’t critical, it may 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 the absence of one can block your Nest from getting sufficient 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 need a Nest Power Connector.
With installation of a Nest Power Connector, you may notice error code E297 show up. 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 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 could even be a fire hazard. If you notice this error code show up on your Nest thermostat and want to take steps to prevent electrical damage, it’s recommended to turn the power off straightaway. You can then get a hold of a professional technician with the appropriate experience diagnosing and solving electrical malfunctions.
e73 - Critical
When your thermostat displays error code e73, it indicates 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 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 speak with a local professional.