Operating a Nest thermostat is one of the best ways to perfect the day-to-day schedule of your heating and cooling. This smart thermostat can learn 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 precise error code offers useful information about the source of the problem, something a trained technician can use to present solutions that much sooner.

Here are seven of the most frequent error codes you may discover on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you can solve it and the projected cost to do so. Remember that while the costs will ultimately be dependent on the specific Nest model, you can count on paying around $75-$200 for repairs. This should include travel and labor costs on top of any specific hardware needed to finish repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and appears 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 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 could have appeared further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A trained technician should inspect electrical connections and wiring until they uncover the source of the problem.

e294 – Critical

Critical error code e294 appears 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 conduct a factory reset of your thermostat to make sure it’s not just a software error. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin inspecting connectors.

They’ll disconnect the power and gradually check each wire, making sure they are fully inserted into the connector with the correct amount of exposed copper. Once they locate the problem connector, it can be swapped for a new one.

e195 – Critical

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

As this error can drain 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 detach the thermostat from its base and provide power through a USB cable. In the event it reveals error code 195, you can continue to visually inspect components like the wiring as well as your air conditioner’s air filter or drainage system. If you can’t find anything wrong with these components, it will likely be best to contact 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 receiving more power than needed. This can stem from the breaker box, an error from the control board or through a faulty connection in the thermostat. The technician can meticulously inspect and test the Nest’s electrical system to determine where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

While this error code isn’t critical, it can still prevent you from using the Nest thermostat how you want 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 examine the Nest’s C connector for the presence of a C wire and adapt the wiring itself if there is. If not, you’ll need a Nest Power Connector.

Due to installation of a Nest Power Connector, you will sometimes notice error code E297 be displayed. This can be dealt with 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

Just like error code e103, e104 is a critical error originating from an overcurrent. If too much power is being delivered inside the Nest’s wiring, it can damage internal components and could even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to guard against 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 necessary experience detecting and fixing electrical problems.

e73 – Critical

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

This will sometimes be as easy as the breaker being turned off, but it can also be something with the wiring. After switching off the power to your HVAC system and thermostat, you can visually examine the wires to make sure they’re not loose or damaged. If nothing looks to be out of place, it’s time to get in touch with a local professional.