Installing a Nest thermostat is one of the best ways to perfect the day-to-day schedule of your HVAC system. This smart thermostat can recognize your preferences and automatically make changes. But as you can expect, it won’t work correctly or at all if you see an error code appear. The specific error code provides useful information about the underlying problem, something a knowledgeable technician can use to provide solutions that much quicker.
Let's consider seven of the most common error codes you might discover on your Nest thermostat. We’ll explain the basics of each error code on top of how you can address it and the estimated cost to do so. Don't forget that while the costs will ultimately depend on the specific Nest model, you can count on paying between $75-$200 for repairs. This should include things like travel and labor costs along with any specific parts needed to finish repairs.
e298 - Critical
This critical error code is limited to newer models of the Nest thermostat and appears when the power is disconnected from the system. Since 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 resolved.
Losing power to your Nest thermostat can be for several reasons. The wiring might have disconnected or become damaged, or a disconnection could have occurred further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician should examine electrical connections and wiring until they find the root of the problem.
e294 - Critical
Critical error code e294 shows up when your Nest thermostat’s wiring needs to be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to make sure it’s not merely a software problem. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start inspecting connectors.
They’ll disconnect the power and slowly inspect each wire, ensuring they are fully placed into the connector with the proper amount of exposed copper. When they find the problem 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 break down and stop giving power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will subsequently shut down. Presuming the breakers are on, you can inspect a handful of other places before consulting a professional technician.
Since this error can drain 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. In the event it presents error code 195, you can continue to visually inspect components such as the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to find anything wrong with these components, it will probably be best to contact a pro.
e103 - Critical
Another critical error code, e103 suggests an electrical problem with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is receiving more power than necessary. This may stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. A technician will cautiously inspect and test the Nest’s electrical system to determine where the power is surging or why the thermostat is convinced there’s an overcurrent problem.
Although this error code isn’t critical, it can still keep you from using the Nest thermostat like normal. 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 getting sufficient power. You can inspect the Nest’s C connector for the presence of a C wire and adapt 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 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 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 excessive power is sent inside 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 guard against electrical damage, it’s suggested to turn the power off as soon as you can. You can then get a hold of a professional technician with the proper experience detecting and solving electrical issues.
e73 - Critical
When your thermostat displays error code e73, it indicates that the Rc wire is not getting power. This may be as simple as the breaker being switched off, but it could also be a problem with the wiring. After switching 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 best to get in touch with a local professional.