Installing a Nest thermostat is one of the easiest ways to improve the daily schedule of your HVAC system. This smart thermostat can learn 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 appear. The specific error code offers useful information about the root of the problem, something a knowledgeable technician can use to offer solutions that much sooner.
Listed below are seven of the most common error codes you could find on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you can fix it and the approximate cost to do so. Keep in mind that while the price will ultimately depend on the exact Nest model, you can expect to pay about $75-$200 for repairs. This should include things like travel and labor costs on top of any specific components required to complete 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 continue to be displayed 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 the electrical system. This might be the circuit breaker, fuse box or system switch. A certified technician should inspect electrical connections and wiring until they locate the source of the problem.
e294 - Critical
Critical error code e294 is displayed 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 complete a factory reset of your thermostat to ensure it’s not just a software issue. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin looking at connectors.
They’ll disconnect the power and gradually inspect each wire, making sure they are fully placed into the connector with the proper amount of uncovered copper. When they find the problem connector, it can be replaced for a new one.
e195 - Critical
This critical error code can show up when the weather outside is especially 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 power down. In the event the breakers are on, you can examine a handful of other places before consulting a professional technician.
As this error can consume your thermostat’s battery, the first step might 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 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 don’t detect anything wrong with these components, it will likely be best to get in touch with a pro.
e103 - Critical
Another critical error code, e103 suggests an electrical problem with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is experiencing more power than needed. This can stem from the breaker box, an error from the control board or thanks to a faulty connection in the thermostat. The technician will cautiously inspect and test the Nest’s electrical system to determine where the power is surging or why the thermostat is convinced there’s an overcurrent problem.
While this error code isn’t critical, it can 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 examine the Nest’s C connector for the presence of a C wire and adapt 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 be displayed. This can be dealt with 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
Just like error code e103, e104 is a critical error that's the result of an overcurrent. If excessive power is sent inside the Nest’s wiring, it could damage internal components and could even be a fire hazard. If you notice this error code show up on your Nest thermostat and want to take steps to prevent electrical damage, it’s recommended to shut the power off as soon as possible. You can then contact a professional technician with the necessary experience detecting and fixing 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 turned off, but it can also be a problem 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 appears to be out of place, it’s a good idea to get in touch with a local professional.