Operating a Nest thermostat is one of the most convenient ways to optimize the daily schedule of your HVAC system. This smart thermostat can recognize your preferences and automatically make adjustments. But as you might expect, it won’t work well or at all if you see an error code appear. The specific error code supplies useful information about the underlying problem, something a trained technician can use to offer solutions that much quicker.

Here are seven of the most common error codes you could 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. Remember that while the investment will ultimately be dependent on the exact Nest model, you can count on paying about $75-$200 for repairs. This should also cover travel and labor costs as well as any specific components required to complete repairs.

e298 – Critical

This critical error code is limited to newer models of the Nest thermostat and shows up when the power is detached from the system. 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 issue is resolved.

Losing power to your Nest thermostat can be for a number of reasons. The wiring might have disconnected or become damaged, or a disconnection might have occurred further along in the electrical system. This might be the circuit breaker, fuse box or system switch. A knowledgeable technician can inspect electrical connections and wiring until they uncover the root 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 should reconfigure the R wire. They’ll first complete a factory reset of your thermostat to ensure it’s not merely a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin checking connectors.

They’ll disconnect the power and gradually inspect each wire, ensuring they are fully attached into the connector with the correct amount of bare copper. When they find the problem connector, it can be swapped for a new one.

e195 – Critical

This critical error code can surface 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 eventually turn off. Assuming the breakers are on, you can examine a handful of other places before consulting a professional technician.

Because this error can deplete your thermostat’s battery, the first step may be supplying enough power to find out if this specific error code is what you’re working with. You can disconnect the thermostat from its base and supply power with a USB cable. Assuming it reveals error code 195, you should continue to visually examine components including the wiring as well as your air conditioner’s air filter or drainage system. If you don’t detect anything wrong with these components, it will likely be best to get in touch with a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical malfunction with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is experiencing more power than what is safe and normal. This can stem from the breaker box, an error from the control board or thanks to a defective connection in the thermostat. The technician needs to carefully examine 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

Even though this error code isn’t critical, it may still prevent you from using the Nest thermostat how you prefer to. Error code n260 refers to 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 adapt 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 appear. 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 originating from an overcurrent. If excess power is being delivered inside the Nest’s wiring, it can damage internal components and could 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 contact a professional technician with the necessary experience diagnosing and resolving electrical malfunctions.

e73 – Critical

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

This may be as easy as the breaker being shut off, but it may also be an issue with the wiring. After switching off the power to your HVAC system and thermostat, you can visually examine the wires to make sure none of them are loose or damaged. If nothing appears to be out of place, it’s best to contact a local professional.