Operating a Nest thermostat is one of the best ways to optimize the day-to-day schedule of your comfort system. This smart thermostat can be taught 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 on the display. The exact error code offers useful information about the root of the problem, something a trained technician can use to offer solutions that much quicker.
Listed below are seven of the most likely error codes you could discover on your Nest thermostat. We’ll review the basics of each error code along with how you might fix it and the projected cost to do so. Keep in mind that while the price will ultimately be dependent on the exact Nest model, you can count on paying about $75-$200 for repairs. This should also cover travel and labor costs along with any specific components required to wrap up repairs.
e298 - Critical
This critical error code is limited to the latest models of the Nest thermostat and appears when the power is shut off. As 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 dealt with.
Losing power to your Nest thermostat can be for a number of reasons. The wiring could have disconnected or become damaged, or a disconnection may have happened further along in the electrical system. This may be the circuit breaker, fuse box or system switch. A knowledgeable technician can 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 has to be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not simply a software issue. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin looking at connectors.
They’ll shut off the power and progressively check each wire, seeing to it that they are fully inserted into the connector with the proper amount of bare copper. When they locate the problem connector, it can be exchanged for a new one.
e195 - Critical
This critical error code can surface when the weather outside is severely hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will subsequently shut down. In the event the breakers are on, you can search a couple of other places before calling a professional technician.
As this error can consume your thermostat’s battery, the first step could be restoring enough power to figure out if this specific error code is what you’re facing. You can detach the thermostat from its base and deliver power by using a USB cable. Assuming it displays error code 195, you can continue to visually check components like the wiring as well as your air conditioner’s air filter or drainage system. If you can't uncover anything wrong with these components, it will likely be best to call a pro.
e103 - Critical
Another critical error code, e103 signifies an electrical malfunction with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is getting more power than what is safe and normal. This can stem from the breaker box, an error from the control board or through a faulty connection in the thermostat. Your technician needs to carefully investigate and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes there’s an overcurrent problem.
Although this error code isn’t critical, it could still stop you from using the Nest thermostat like normal. Error code n260 concerns the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from obtaining sufficient power. You can check 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.
Due to installation of a Nest Power Connector, you will sometimes notice error code E297 be displayed. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already 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 stemming from an overcurrent. If excess power is sent through the Nest’s wiring, it may 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 suggested to turn the power off straightaway. You can then get in touch with a professional technician with the necessary experience diagnosing and fixing electrical damage.
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 an issue with the wiring. After turning 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 seems to be out of place, it’s time to get in touch with a local professional.