Installing a Nest thermostat is one of the most convenient ways to perfect the everyday 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 correctly or at all if you see an error code appear. The exact error code offers useful information about the underlying problem, something a knowledgeable technician can use to present solutions that much faster.
Let's consider seven of the most common error codes you might encounter on your Nest thermostat. We’ll explain the basics of each error code on top of how you could address 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 about $75-$200 for repairs. This should include things like travel and labor costs along with any specific parts 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 shut off. As 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 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 could have occurred further along in your home's electrical system. This might be the circuit breaker, fuse box or system switch. A certified technician will inspect 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 has to be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not just a software issue. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start checking connectors.
They’ll shut off the power and slowly check each wire, making sure they are fully placed into the connector with the proper amount of bare copper. When they pinpoint 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 break down and stop sending power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will finally turn off. Assuming the breakers are on, you can examine a handful of other places before consulting a professional technician.
Since this error can drain your thermostat’s battery, the first step could 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 by using a USB cable. If it reveals error code 195, you should continue to visually examine components such as the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to 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 will refer to an overcurrent problem, which means the wiring is receiving more power than necessary. This can stem from the breaker box, an error from the control board or through a defective connection in the thermostat. The technician will meticulously 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.
Even though this error code isn’t critical, it could still stop 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 receiving 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 need a Nest Power Connector.
Due to installation of a Nest Power Connector, you might notice error code E297 be displayed. 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
Just like error code e103, e104 is a critical error stemming from an overcurrent. If excess power is transported using 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 suggested to switch the power off straightaway. You can then contact a professional technician with the necessary experience diagnosing and fixing electrical problems.
e73 - Critical
When your thermostat displays error code e73, it indicates that the Rc wire is not receiving power. This may be as easy as the breaker being shut off, but it could also be something with the wiring. After turning 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 a good idea to contact a local professional.