Using a Nest thermostat is one of the easiest ways to optimize the everyday schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make improvements. But as you may expect, it won’t work well or at all if you see an error code show up. The precise error code provides useful information about the underlying problem, something a trained technician can use to provide solutions that much faster.

Let’s consider seven of the most likely error codes you might encounter on your Nest thermostat. We’ll review the basics of each error code on top of how you might fix it and the approximate cost to do so. Don’t forget that while the investment will ultimately be dependent on the specific Nest model, you can expect to pay between $75-$200 for repairs. This should also cover travel and labor costs as well as any specific components required to wrap up repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and appears when the power is disconnected from the system. Since 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 issue is dealt with.

Losing power to your Nest thermostat can be for several reasons. The wiring could have disconnected or become damaged, or a disconnection could have happened further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A trained technician should examine 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 should reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to ensure it’s not merely a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start inspecting connectors.

They’ll disconnect the power and gradually inspect each wire, ensuring they are fully attached into the connector with the correct amount of exposed copper. Once they locate the damaged connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can appear when the weather outside is particularly hot. The HVAC system can shut down and stop delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will subsequently power down. Presuming the breakers are on, you can check a few other places before consulting a professional technician.

As this error can consume your thermostat’s battery, the first step might be providing 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 with a USB cable. Assuming it presents error code 195, you may continue to visually check components including 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 will likely be best to contact a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical problem with your Nest thermostat. More specifically, e103 will 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 because of a faulty connection in the thermostat. A technician needs to meticulously investigate and test the Nest’s electrical system to understand where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

Although this error code isn’t critical, it may still stop 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 missing one can block your Nest from obtaining enough power. You can examine the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you can get 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 has already been installed, you’ll instead have to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.

e104 – Critical

Like error code e103, e104 is a critical error originating from an overcurrent. If excessive power is sent inside the Nest’s wiring, it could damage internal components and may even be a fire hazard. If you see this error code appear on your Nest thermostat and want to guard against electrical damage, it’s recommended to switch the power off as soon as possible. You can then contact a professional technician with the necessary experience identifying and solving electrical malfunctions.

e73 – Critical

When your thermostat displays error code e73, it means that the Rc wire is not receiving power.

This will sometimes be as straightforward as the breaker being switched off, but it may 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 seems to be out of place, it’s time to speak with a local professional.