Using 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 well or at all if you see an error code show up. The specific error code offers useful information about the source of the problem, something a trained technician can use to offer solutions that much sooner.
Listed below are seven of the most likely error codes you could encounter on your Nest thermostat. We’ll review the basics of each error code on top of how you could fix it and the estimated cost to do so. Keep in mind that while the costs will ultimately be dependent on the specific Nest model, you can count on paying about $75-$200 for repairs. This should also cover travel and labor costs on top of any specific hardware required to complete repairs.
e298 - Critical
This critical error code is limited to the latest models of the Nest thermostat and appears when the power is detached from the system. Because this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on the screen until the problem 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 may have appeared further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A knowledgeable technician will examine electrical connections and wiring until they uncover 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 conduct a factory reset of your thermostat to make sure it’s not simply a software problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start inspecting connectors.
They’ll disconnect the power and slowly check each wire, seeing to it that they are fully inserted into the connector with the proper amount of bare copper. Once they find the malfunctioning connector, it can be swapped 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 subsequently power down. In the event the breakers are on, you can inspect a few other places before contacting a professional technician.
Because this error can drain your thermostat’s battery, the first step might be providing enough power to determine if this specific error code is what you’re working with. You can detach the thermostat from its base and supply power through a USB cable. In the event it presents error code 195, you should continue to visually check components such as the wiring as well as your air conditioner’s air filter or drainage system. If you don’t find anything wrong with these components, it will probably be best to call a pro.
e103 - Critical
Another critical error code, e103 indicates 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 what is safe and normal. This can stem from the breaker box, an error from the control board or through a defective connection in the thermostat. A technician needs to meticulously inspect 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.
While this error code isn’t critical, it might still stop you from using the Nest thermostat how you want to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining 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 can get a Nest Power Connector.
With installation of a Nest Power Connector, you might notice error code E297 show up. 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 being delivered inside the Nest’s wiring, it can damage internal components and can 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 recommended to turn the power off as soon as possible. You can then get in touch with a professional technician with the proper experience identifying and solving 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 straightforward 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 nothing is loose or damaged. If nothing looks to be out of place, it’s time to get in touch with a local professional.