Installing a Nest thermostat is one of the easiest ways to improve the everyday schedule of your HVAC system. This smart thermostat can learn your preferences and automatically make improvements. But as you might expect, it won’t work properly or at all if you see an error code appear. The exact error code offers useful information about the source of the problem, something a trained technician can use to present solutions that much quicker.
Let's consider seven of the most frequent error codes you might discover on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you could fix it and the approximate cost to do so. Remember that while the price will ultimately depend on the precise Nest model, you can anticipate paying about $75-$200 for repairs. This should also cover travel and labor costs on top of any specific components needed to finish 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. 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 fixed.
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 your home's electrical system. This could be the circuit breaker, fuse box or system switch. A trained technician can check electrical connections and wiring until they find the root of the problem.
e294 - Critical
Critical error code e294 is displayed when your Nest thermostat’s wiring should be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first complete a factory reset of your thermostat to make sure it’s not simply a software issue. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin inspecting connectors.
They’ll shut off the power and slowly check each wire, making sure they are fully inserted into the connector with the correct amount of uncovered copper. Once they find the damaged connector, it can be exchanged for a new one.
e195 - Critical
This critical error code can show up when the weather outside is severely hot. The HVAC system can break down and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will subsequently shut down. Presuming the breakers are on, you can check a few other places before calling a professional technician.
Because this error can deplete your thermostat’s battery, the first step could be supplying enough power to figure out if this specific error code is what you’re facing. You can disconnect the thermostat from its base and deliver power by using a USB cable. Assuming it presents error code 195, you should continue to visually check components such as the wiring as well as your air conditioner’s air filter or drainage system. If you can't find anything wrong with these components, it's maybe best to get in touch with 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 will sometimes stem from the breaker box, an error from the control board or thanks to a defective connection in the thermostat. Your technician will 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 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 the absence of one can block your Nest from obtaining adequate 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 will sometimes notice error code E297 show up. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead need 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 using the Nest’s wiring, it could damage internal components and may even be a fire hazard. If you see this error code show up on your Nest thermostat and want to take steps to prevent electrical damage, it’s a good idea to shut the power off straightaway. You can then get in touch with a professional technician with the proper experience diagnosing and solving electrical malfunctions.
e73 - Critical
When your thermostat displays error code e73, it signifies that the Rc wire is not receiving power. This will sometimes be as simple 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 check the wires to make sure they’re not loose or damaged. If nothing looks to be out of place, it’s time to speak with a local professional.