Operating a Nest thermostat is one of the best ways to improve the daily schedule of your HVAC 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 provides useful information about the root of the problem, something a professional technician can use to present solutions that much faster.

Here are seven of the most likely error codes you may encounter on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you might solve it and the estimated cost to do so. Keep in mind that while the price will ultimately depend on the specific Nest model, you can count on paying about $75-$200 for repairs. This should include travel and labor costs on top of any specific components necessary 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 shut off. Because 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 resolved.

Losing power to your Nest thermostat can be for numerous reasons. The wiring could have disconnected or become damaged, or a disconnection could have occurred further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A trained technician should check 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 has to be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not just a software problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin inspecting connectors.

They’ll detach the power and progressively inspect each wire, ensuring they are fully attached into the connector with the correct amount of bare copper. After they locate the damaged connector, it can be swapped for a new one.

e195 – Critical

This critical error code can surface when the weather outside is particularly hot. The HVAC system can fail and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will eventually power down. In the event the breakers are on, you can search a couple of other places before calling a professional technician.

Since this error can drain your thermostat’s battery, the first step might be providing enough power to figure out if this specific error code is what you’re facing. You can separate the thermostat from its base and provide power through a USB cable. If it reveals error code 195, you can continue to visually examine components like the wiring as well as your air conditioner’s air filter or drainage system. If you can’t uncover anything wrong with these components, it will likely be best to contact a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical issue with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is receiving more power than needed. This may stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. Your technician should meticulously examine and test the Nest’s electrical system to figure out where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

While this error code isn’t critical, it may 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 getting enough power. You can check the Nest’s C connector for the presence of a C wire and modify 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 remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already 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 originating from an overcurrent. If too much power is transported through the Nest’s wiring, it can damage internal components and may even be a fire hazard. If you notice this error code show up on your Nest thermostat and want to guard against electrical damage, it’s suggested to switch the power off as soon as possible. You can then get a hold of a professional technician with the proper experience identifying and resolving electrical problems.

e73 – Critical

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

This will sometimes be as simple as the breaker being turned off, but it could also be an issue 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 time to speak with a local professional.