Operating a Nest thermostat is one of the most convenient ways to improve the everyday schedule of your comfort system. This smart thermostat can learn your preferences and automatically make adjustments. But as you may expect, it won’t work properly or at all if you see an error code show up. The exact error code provides useful information about the underlying problem, something a professional technician can use to present solutions that much sooner.
Let's consider seven of the most frequent error codes you could encounter on your Nest thermostat. We’ll explain the basics of each error code as well as how you might solve it and the approximate cost to do so. Keep in mind that while the costs will ultimately hinge on the exact Nest model, you can count on paying about $75-$200 for repairs. This should include travel and labor costs on top of any specific components required 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 detached from the system. Because this is a critical power error, the thermostat will swap to the backup battery system. The error message will remain on display until the issue is dealt with.
Losing power to your Nest thermostat can be for a number of reasons. The wiring might have disconnected or become damaged, or a disconnection might have occurred further along in your home's electrical system. This might be the circuit breaker, fuse box or system switch. A knowledgeable technician will check 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 has to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first complete 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 looking at connectors.
They’ll shut off the power and progressively look at each wire, seeing to it that they are fully attached into the connector with the correct amount of exposed copper. Once they find the malfunctioning 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 sending power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will subsequently power down. In the event the breakers are on, you can search a handful of other places before calling a professional technician.
Because this error can drain your thermostat’s battery, the first step might be supplying enough power to figure out if this specific error code is what you’re working with. You can detach the thermostat from its base and supply power by using a USB cable. Assuming it displays error code 195, you can continue to visually examine components like the wiring as well as your air conditioner’s air filter or drainage system. If you don’t uncover anything wrong with these components, it's maybe best to contact a pro.
e103 - Critical
Another critical error code, e103 signifies an electrical error with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is receiving more power than needed. This will sometimes stem from the breaker box, an error from the control board or because of a bad connection in the thermostat. Your technician can 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.
While this error code isn’t critical, it might still stop you from using the Nest thermostat like normal. Error code n260 refers to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining adequate 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.
Due to installation of a Nest Power Connector, you may notice error code E297 appear. 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
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 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 take steps to prevent electrical damage, it’s a good idea to shut the power off straightaway. You can then get in touch with a professional technician with the proper experience detecting and solving electrical problems.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not getting power. This will sometimes be as easy as the breaker being shut off, but it can also be something with the wiring. After switching off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure nothing is loose or damaged. If nothing looks to be out of place, it’s best to get in touch with a local professional.