Operating a Nest thermostat is one of the best ways to improve the everyday schedule of your HVAC system. This smart thermostat can be taught your preferences and automatically make improvements. But as you might expect, it won’t work properly or at all if you see an error code on the display. The exact error code offers useful information about the root of the problem, something a professional technician can use to provide solutions that much quicker.

Here are seven of the most likely error codes you could encounter 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 depend on the specific Nest model, you can count on paying around $75-$200 for repairs. This should include travel and labor costs as well as any specific hardware required to complete repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and shows up when the power is disconnected from the system. As 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 dealt with.

Losing power to your Nest thermostat can be for several reasons. The wiring may have disconnected or become damaged, or a disconnection might have happened further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A trained technician will examine electrical connections and wiring until they find the source of the problem.

e294 – Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring needs to be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to ensure it’s not simply a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start looking at connectors.

They’ll detach the power and slowly look at each wire, ensuring they are fully attached into the connector with the correct amount of exposed copper. After they find the malfunctioning connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can show up when the weather outside is severely hot. The HVAC system can shut down and stop delivering power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will subsequently power down. In the event the breakers are on, you can inspect a couple of other places before contacting a professional technician.

Because this error can drain your thermostat’s battery, the first step may be providing 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 provide power with a USB cable. In the event 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 struggle to detect anything wrong with these components, it’s maybe best to get in touch with 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 experiencing more power than needed. This may stem from the breaker box, an error from the control board or through a defective connection in the thermostat. Your technician will carefully investigate and test the Nest’s electrical system to figure out 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 can still stop 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 the absence of one can block your Nest from receiving sufficient power. You can inspect the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you’ll need a Nest Power Connector.

With installation of a Nest Power Connector, you will sometimes notice error code E297 show up. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead be required 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 that’s the result of an overcurrent. If too much power is transported using the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to protect from electrical damage, it’s a good idea to switch the power off as soon as possible. You can then get in touch with a professional technician with the proper experience identifying and solving electrical malfunctions.

e73 – Critical

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

This will sometimes be as straightforward as the breaker being shut off, but it could also be an issue with the wiring. After turning off the power to your HVAC system and thermostat, you can visually examine the wires to make sure nothing is loose or damaged. If nothing appears to be out of place, it’s time to contact a local professional.