Operating a Nest thermostat is one of the most convenient ways to perfect the daily schedule of your comfort system. This smart thermostat can learn your preferences and automatically make changes. But as you may expect, it won’t work correctly or at all if you see an error code appear. The precise error code provides useful information about the underlying problem, something a professional technician can use to provide solutions that much sooner.
Here are seven of the most common error codes you might discover on your Nest thermostat. We’ll walk you through the basics of each error code along with how you can solve it and the approximate cost to do so. Don't forget that while the price will ultimately depend on the precise Nest model, you can count on paying about $75-$200 for repairs. This should include travel and labor costs on top of any specific hardware necessary to wrap up repairs.
e298 - Critical
This critical error code is limited to newer models of the Nest thermostat and is displayed when the power is disconnected 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 could have disconnected or become damaged, or a disconnection might have occurred further along in the electrical system. This may be the circuit breaker, fuse box or system switch. A professional technician will examine electrical connections and wiring until they uncover the root of the problem.
e294 - Critical
Critical error code e294 is displayed when your Nest thermostat’s wiring has to be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first complete a factory reset of your thermostat to ensure it’s not simply a software problem. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start checking connectors.
They’ll shut off the power and gradually inspect each wire, making sure they are fully placed into the connector with the correct amount of bare copper. When they find the problem connector, it can be replaced for a new one.
e195 - Critical
This critical error code can appear when the weather outside is especially hot. The HVAC system can shut down and stop delivering power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will finally shut down. In the event the breakers are on, you can inspect a couple of other places before consulting a professional technician.
As this error can consume your thermostat’s battery, the first step could be supplying enough power to figure out if this specific error code is what you’re dealing with. You can separate the thermostat from its base and deliver power by using a USB cable. Assuming it displays error code 195, you may continue to visually examine components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to 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 issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is receiving more power than needed. This can stem from the breaker box, an error from the control board or because of a faulty connection in the thermostat. The technician can cautiously examine and test the Nest’s electrical system to figure out where the power is surging or why the thermostat thinks there’s an overcurrent problem.
Even though this error code isn’t critical, it may still stop you from using the Nest thermostat like normal. Error code n260 concerns the lack of a C wire or Nest Power Connector, as missing one can block your Nest from obtaining sufficient power. You can examine 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.
During installation of a Nest Power Connector, you may 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 need to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.
e104 - Critical
Just like error code e103, e104 is a critical error that's the result of an overcurrent. If excess power is sent using 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 you can. You can then get a hold of a professional technician with the necessary experience diagnosing and resolving electrical problems.
e73 - Critical
When your thermostat displays error code e73, it signifies that the Rc wire is not getting power. This might be as simple as the breaker being turned off, but it can also be a problem with the wiring. After turning off the power to your HVAC system and thermostat, you can visually examine the wires to make sure none of them are loose or damaged. If nothing appears to be out of place, it’s time to get in touch with a local professional.