Operating a Nest thermostat is one of the easiest ways to perfect the daily schedule of your HVAC system. This smart thermostat can recognize your preferences and automatically make adjustments. But as you may expect, it won’t work well or at all if you see an error code on the display. The exact error code provides useful information about the root of the problem, something a professional technician can use to offer solutions that much faster.

Listed below are seven of the most likely error codes you could find on your Nest thermostat. We’ll review the basics of each error code as well as how you might fix it and the approximate cost to do so. Remember that while the costs will ultimately be dependent on the precise Nest model, you can expect to pay around $75-$200 for repairs. This should include travel and labor costs on top of any specific parts required to finish repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and is displayed when the power is shut off. Since this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on display until the problem is resolved.

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

They’ll shut off the power and progressively check each wire, seeing to it that they are fully inserted into the connector with the proper amount of bare copper. After they pinpoint the problem connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can appear when the weather outside is severely hot. The HVAC system can break down and stop giving power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will subsequently shut down. Presuming the breakers are on, you can inspect a handful of other places before consulting a professional technician.

Since this error can consume your thermostat’s battery, the first step may 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. Assuming it displays 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 don’t uncover anything wrong with these components, it will likely be best to call a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical error with your Nest thermostat. More specifically, e103 will 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 thanks to a defective connection in the thermostat. The technician can cautiously inspect and test the Nest’s electrical system to understand where the power is surging or why the thermostat is convinced there’s an overcurrent problem.

n260

Although this error code isn’t critical, it might 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 not having one can block your Nest from getting sufficient 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.

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 is already 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 that’s the result of an overcurrent. If too much power is sent through the Nest’s wiring, it may damage internal components and may even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to take steps to prevent electrical damage, it’s suggested to switch the power off as soon as you can. You can then get in touch with a professional technician with the appropriate experience diagnosing and resolving electrical issues.

e73 – Critical

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

This could be as straightforward as the breaker being turned off, but it may also be something with the wiring. After turning off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure none of them are loose or damaged. If nothing seems to be out of place, it’s a good idea to contact a local professional.