Operating a Nest thermostat is one of the most convenient ways to optimize the day-to-day schedule of your heating and cooling. This smart thermostat can learn your preferences and automatically make changes. But as you might expect, it won’t work properly or at all if you see an error code appear. 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 frequent error codes you might discover 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. Don't forget that while the price will ultimately be dependent on the precise Nest model, you can count on paying between $75-$200 for repairs. This should include travel and labor costs along with any specific components necessary to finish repairs.
e298 - Critical
This critical error code is limited to newer models of the Nest thermostat and appears when the power is shut off. As this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on display until the problem is dealt with.
Losing power to your Nest thermostat can be for numerous reasons. The wiring could have disconnected or become damaged, or a disconnection may have happened further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A trained technician will inspect electrical connections and wiring until they locate the root of the problem.
e294 - Critical
Critical error code e294 shows up 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 ensure it’s not simply a software error. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin checking connectors.
They’ll detach the power and progressively look at each wire, making sure they are fully inserted into the connector with the correct amount of exposed copper. Once they find the problem connector, it can be swapped for a new one.
e195 - Critical
This critical error code can show up when the weather outside is severely 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 shut down. Presuming the breakers are on, you can inspect a couple of other places before calling a professional technician.
Because this error can consume your thermostat’s battery, the first step might be supplying 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 with a USB cable. If it presents error code 195, you should continue to visually inspect components like the wiring as well as your air conditioner’s air filter or drainage system. If you can't detect anything wrong with these components, it's maybe best to call 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 receiving more power than needed. This will sometimes stem from the breaker box, an error from the control board or through a faulty connection in the thermostat. Your technician will cautiously 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.
Even though this error code isn’t critical, it may still keep you from using the Nest thermostat how you prefer to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as missing one can block your Nest from obtaining 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 need a Nest Power Connector.
With installation of a Nest Power Connector, you may notice error code E297 appear. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead be required to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.
e104 - Critical
Similar to error code e103, e104 is a critical error stemming from an overcurrent. If excess power is sent through the Nest’s wiring, it could damage internal components and could 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 a good idea to shut the power off as soon as you can. You can then get in touch with a professional technician with the proper experience diagnosing and solving electrical issues.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not getting power. This could be as easy as the breaker being switched off, but it may also be something with the wiring. After shutting 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 seems to be out of place, it’s time to speak with a local professional.