Installing a Nest thermostat is one of the best ways to improve the day-to-day 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 knowledgeable technician can use to provide solutions that much faster.

Here are seven of the most common error codes you may encounter on your Nest thermostat. We’ll explain the basics of each error code on top of how you might solve it and the approximate cost to do so. Keep in mind that while the investment will ultimately hinge on the exact Nest model, you can expect to pay about $75-$200 for repairs. This should include things like travel and labor costs on top of any specific components required to wrap up repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and shows up when the power is detached from the system. As this is a critical power error, the thermostat will swap to the backup battery system. The error message will remain on the screen until the issue is resolved.

Losing power to your Nest thermostat can be for numerous reasons. The wiring may have disconnected or become damaged, or a disconnection might have happened further along in your home’s electrical system. This may be the circuit breaker, fuse box or system switch. A professional technician can examine 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, 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 inspecting connectors.

They’ll shut off the power and progressively check each wire, making sure they are fully attached into the connector with the correct amount of exposed copper. After they pinpoint the malfunctioning connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can surface when the weather outside is particularly hot. The HVAC system can break down and stop delivering power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will subsequently power down. Presuming the breakers are on, you can examine a handful of other places before contacting a professional technician.

Since this error can deplete your thermostat’s battery, the first step could be restoring enough power to determine if this specific error code is what you’re facing. You can separate the thermostat from its base and deliver power by using a USB cable. Assuming it reveals error code 195, you may continue to visually inspect components such as 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’s maybe best to call a pro.

e103 – Critical

Another critical error code, e103 signifies an electrical issue with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is getting more power than what is safe and normal. This may stem from the breaker box, an error from the control board or because of a bad connection in the thermostat. The technician needs to carefully 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

Although this error code isn’t critical, it could still stop 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 missing one can block your Nest from receiving enough power. You can examine the Nest’s C connector for the presence of a C wire and adjust 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 show up. This can be remedied 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

Like error code e103, e104 is a critical error stemming from an overcurrent. If too much power is sent using the Nest’s wiring, it could damage internal components and could even be a fire hazard. If you see this error code appear 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 a hold of a professional technician with the necessary experience identifying and fixing electrical malfunctions.

e73 – Critical

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

This will sometimes be as easy 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 examine the wires to make sure they’re not loose or damaged. If nothing seems to be out of place, it’s best to contact a local professional.