Using a Nest thermostat is one of the most convenient ways to optimize the everyday schedule of your comfort system. This smart thermostat can learn your preferences and automatically make improvements. But as you may expect, it won’t work well or at all if you see an error code on the display. The specific error code supplies useful information about the source of the problem, something a knowledgeable technician can use to provide solutions that much sooner.
Here are seven of the most likely error codes you might encounter on your Nest thermostat. We’ll explain the basics of each error code on top of how you can 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 between $75-$200 for repairs. This should include things like travel and labor costs as well as any specific parts necessary to complete repairs.
e298 - Critical
This critical error code is limited to the latest models of the Nest thermostat and shows up 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 continue to be displayed until the problem is fixed.
Losing power to your Nest thermostat can be for several reasons. The wiring might have disconnected or become damaged, or a disconnection may have happened further along in the electrical system. This might be the circuit breaker, fuse box or system switch. A certified 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 needs to be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first complete a factory reset of your thermostat to make sure it’s not simply a software error. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin looking at connectors.
They’ll disconnect the power and slowly inspect each wire, seeing to it that they are fully attached into the connector with the proper amount of exposed copper. When they pinpoint the malfunctioning connector, it can be swapped for a new one.
e195 - Critical
This critical error code can surface when the weather outside is especially hot. The HVAC system can fail and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will eventually power down. In the event the breakers are on, you can search a handful of other places before consulting a professional technician.
Since this error can drain your thermostat’s battery, the first step may be supplying enough power to determine if this specific error code is what you’re working with. You can separate the thermostat from its base and deliver power through a USB cable. In the event it reveals 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 detect anything wrong with these components, it will probably be best to contact a pro.
e103 - Critical
Another critical error code, e103 signifies an electrical malfunction with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is getting more power than needed. This will sometimes stem from the breaker box, an error from the control board or through a defective connection in the thermostat. Your technician will meticulously investigate and test the Nest’s electrical system to understand where the power is surging or why the thermostat is convinced there’s an overcurrent problem.
While this error code isn’t critical, it might still keep 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 receiving enough power. You can examine the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you can get a Nest Power Connector.
During installation of a Nest Power Connector, you will sometimes notice error code E297 show up. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been installed, you’ll instead have 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 excess power is being delivered inside the Nest’s wiring, it can damage internal components and may even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to guard against electrical damage, it’s suggested to shut the power off as soon as possible. You can then get in touch with a professional technician with the appropriate experience diagnosing and fixing electrical damage.
e73 - Critical
When your thermostat displays error code e73, it signifies that the Rc wire is not getting power. This may be as easy as the breaker being shut off, but it can also be a problem with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually check the wires to make sure none of them are loose or damaged. If nothing looks to be out of place, it’s a good idea to contact a local professional.