Using a Nest thermostat is one of the most convenient ways to optimize the daily schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make changes. But as you may 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 quicker.
Let's consider seven of the most common error codes you might discover on your Nest thermostat. We’ll review the basics of each error code along with how you can solve it and the estimated cost to do so. Don't forget that while the price will ultimately be dependent on the exact Nest model, you can count on paying around $75-$200 for repairs. This should include things like travel and labor costs on top of any specific parts necessary to wrap up repairs.
e298 - Critical
This critical error code is limited to the latest models of the Nest thermostat and is displayed when the power is shut off. Since this is a critical power error, the thermostat will change to the backup battery system. The error message will continue to be displayed until the issue is fixed.
Losing power to your Nest thermostat can be for numerous reasons. The wiring may have disconnected or become damaged, or a disconnection might have occurred further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A trained technician can examine electrical connections and wiring until they uncover the source of the problem.
e294 - Critical
Critical error code e294 appears 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 ensure it’s not just a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin checking connectors.
They’ll detach the power and progressively check each wire, ensuring they are fully inserted into the connector with the proper amount of exposed copper. Once they pinpoint the problem connector, it can be exchanged for a new one.
e195 - Critical
This critical error code can show up when the weather outside is particularly hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will subsequently shut down. In the event the breakers are on, you can check a few other places before contacting a professional technician.
Since this error can consume your thermostat’s battery, the first step might be providing enough power to figure out if this specific error code is what you’re facing. You can separate the thermostat from its base and provide power through a USB cable. Assuming it displays error code 195, you may continue to visually check components including 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 will likely be best to contact a pro.
e103 - Critical
Another critical error code, e103 indicates an electrical problem 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 may stem from the breaker box, an error from the control board or because of a faulty connection in the thermostat. A technician needs to cautiously examine and test the Nest’s electrical system to figure out where the power is surging or why the thermostat is convinced there’s an overcurrent problem.
While this error code isn’t critical, it could still stop you from using the Nest thermostat how you prefer to. 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.
With installation of a Nest Power Connector, you may notice error code E297 be displayed. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead have 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 transported through the Nest’s wiring, it can damage internal components and could even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to take steps to prevent electrical damage, it’s recommended to turn the power off straightaway. You can then get in touch with a professional technician with the necessary experience diagnosing and resolving electrical malfunctions.
e73 - Critical
When your thermostat displays error code e73, it signifies that the Rc wire is not receiving power. This might be as straightforward as the breaker being switched off, but it may also be a problem with the wiring. After turning off the power to your HVAC system and thermostat, you can visually check the wires to make sure they’re not loose or damaged. If nothing seems to be out of place, it’s time to get in touch with a local professional.