Using a Nest thermostat is one of the best ways to perfect the daily schedule of your heating and cooling. This smart thermostat can learn your preferences and automatically make improvements. But as you might expect, it won’t work well or at all if you see an error code show up. The exact error code offers useful information about the source of the problem, something a professional technician can use to provide solutions that much sooner.
Let's consider seven of the most common error codes you could find on your Nest thermostat. We’ll review the basics of each error code on top of how you can address it and the estimated cost to do so. Remember 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 as well as any specific hardware necessary to wrap up repairs.
e298 - Critical
This critical error code is limited to newer models of the Nest thermostat and shows up 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 remain on the screen until the problem is fixed.
Losing power to your Nest thermostat can be for a number of reasons. The wiring may have disconnected or become damaged, or a disconnection could have appeared further along in your home's electrical system. This might 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 appears when your Nest thermostat’s wiring has to be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to ensure it’s not merely a software problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start checking connectors.
They’ll shut off the power and gradually inspect each wire, ensuring they are fully inserted into the connector with the proper amount of uncovered copper. After they pinpoint the malfunctioning connector, it can be replaced for a new one.
e195 - Critical
This critical error code can surface when the weather outside is severely hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will finally shut down. Assuming the breakers are on, you can examine a handful of other places before calling a professional technician.
Since this error can drain your thermostat’s battery, the first step may be supplying enough power to figure out if this specific error code is what you’re working with. You can separate the thermostat from its base and supply power by using a USB cable. If it reveals error code 195, you may continue to visually check components like 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's maybe best to get in touch with a pro.
e103 - Critical
Another critical error code, e103 indicates an electrical problem with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is receiving more power than necessary. This can stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. The technician will carefully investigate 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 prefer to. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from receiving 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 can get a Nest Power Connector.
Due to installation of a Nest Power Connector, you will sometimes notice error code E297 appear. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector is 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 originating from an overcurrent. If excess power is sent using the Nest’s wiring, it may damage internal components and could even be a fire hazard. If you see this error code appear on your Nest thermostat and want to guard against electrical damage, it’s suggested to switch the power off as soon as possible. You can then contact a professional technician with the proper experience detecting and solving 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 easy as the breaker being shut off, but it could also be an issue with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually check the wires to make sure nothing is loose or damaged. If nothing appears to be out of place, it’s a good idea to speak with a local professional.