Operating a Nest thermostat is one of the best ways to improve the day-to-day schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make improvements. But as you might expect, it won’t work correctly or at all if you see an error code appear. The precise error code offers useful information about the source of the problem, something a professional technician can use to offer solutions that much sooner.
Here are seven of the most frequent error codes you might find on your Nest thermostat. We’ll walk you through the basics of each error code along with how you could fix it and the approximate cost to do so. Keep in mind that while the price will ultimately be dependent on the specific Nest model, you can expect to pay around $75-$200 for repairs. This should include things like travel and labor costs along with any specific parts 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 disconnected from the system. Because 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 resolved.
Losing power to your Nest thermostat can be for a number of reasons. The wiring could have disconnected or become damaged, or a disconnection might have happened further along in the electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician should check electrical connections and wiring until they uncover the source 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 will need to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to make sure it’s not merely a software issue. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin checking connectors.
They’ll shut off the power and gradually look at each wire, making sure they are fully inserted into the connector with the correct amount of bare copper. Once they pinpoint the malfunctioning connector, it can be replaced for a new one.
e195 - Critical
This critical error code can appear when the weather outside is severely hot. The HVAC system can shut down and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will finally shut down. Presuming the breakers are on, you can examine a handful of other places before contacting a professional technician.
Because this error can deplete your thermostat’s battery, the first step might be supplying enough power to find out if this specific error code is what you’re working with. You can detach the thermostat from its base and supply power through a USB cable. If it displays error code 195, you should continue to visually inspect components such as the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to detect anything wrong with these components, it's maybe best to call a pro.
e103 - Critical
Another critical error code, e103 signifies an electrical error with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is experiencing more power than needed. This will sometimes stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. The technician will meticulously inspect and test the Nest’s electrical system to understand where the power is surging or why the thermostat thinks there’s an overcurrent problem.
Even though this error code isn’t critical, it might still prevent you from using the Nest thermostat how you prefer to. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as missing one can block your Nest from getting 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.
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 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 too much power is being delivered through the Nest’s wiring, it can 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 suggested to shut the power off as soon as you can. You can then get a hold of a professional technician with the necessary experience detecting and fixing electrical damage.
e73 - Critical
When your thermostat displays error code e73, it signifies that the Rc wire is not getting power. This could be as simple as the breaker being shut off, but it can also be an issue 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 contact a local professional.