Using a Nest thermostat is one of the most convenient ways to improve the everyday schedule of your comfort system. This smart thermostat can be taught your preferences and automatically make improvements. But as you may expect, it won’t work properly or at all if you see an error code on the display. The precise error code provides useful information about the root of the problem, something a trained technician can use to offer solutions that much sooner.
Listed below are seven of the most frequent error codes you may encounter on your Nest thermostat. We’ll walk you through the basics of each error code along with how you can fix it and the approximate cost to do so. Don't forget that while the price will ultimately be dependent on the exact Nest model, you can expect to pay between $75-$200 for repairs. This should include things like travel and labor costs as well as any specific components necessary 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 switch 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 numerous reasons. The wiring could have disconnected or become damaged, or a disconnection might have occurred further along in your electrical system. This might be the circuit breaker, fuse box or system switch. A trained technician will inspect electrical connections and wiring until they uncover 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 will need to reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to make sure it’s not simply a software error. 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 progressively check each wire, ensuring they are fully placed into the connector with the correct amount of bare copper. After they pinpoint the malfunctioning connector, it can be exchanged for a new one.
e195 - Critical
This critical error code can surface when the weather outside is particularly hot. The HVAC system can break down and stop delivering power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will subsequently shut down. Assuming the breakers are on, you can check a couple of other places before calling a professional technician.
Because this error can drain your thermostat’s battery, the first step could be restoring enough power to figure out if this specific error code is what you’re dealing with. You can detach the thermostat from its base and provide power through a USB cable. In the event it displays error code 195, you can continue to visually inspect components such as the wiring as well as your air conditioner’s air filter or drainage system. If you don’t uncover 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 will refer to an overcurrent problem, which means the wiring is getting 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. A technician can meticulously inspect and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes there’s an overcurrent problem.
While this error code isn’t critical, it could still keep you from using the Nest thermostat how you want 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 enough 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.
During 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 has already been installed, you’ll instead have 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 transported using the Nest’s wiring, it may damage internal components and can 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 suggested to turn the power off as soon as you can. You can then get in touch with a professional technician with the necessary experience detecting and solving electrical problems.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not receiving power. This may be as straightforward 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 check the wires to make sure none of them are loose or damaged. If nothing looks to be out of place, it’s best to contact a local professional.