Installing a Nest thermostat is one of the easiest ways to improve the day-to-day schedule of your HVAC system. This smart thermostat can be taught your preferences and automatically make improvements. But as you can expect, it won’t work well or at all if you see an error code on the display. The specific error code offers useful information about the root of the problem, something a trained technician can use to offer solutions that much faster.

Here are seven of the most common error codes you may discover on your Nest thermostat. We’ll explain the basics of each error code as well as how you can address it and the approximate cost to do so. Keep in mind that while the price will ultimately be dependent on the precise Nest model, you can anticipate paying between $75-$200 for repairs. This should include travel and labor costs on top of any specific hardware necessary to wrap up repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and appears when the power is shut off. Since 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 dealt with.

Losing power to your Nest thermostat can be for several reasons. The wiring could have disconnected or become damaged, or a disconnection could have occurred further along in the electrical system. This may be the circuit breaker, fuse box or system switch. A certified technician can check 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 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 simply a software error. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start inspecting connectors.

They’ll disconnect the power and gradually inspect each wire, seeing to it that they are fully inserted into the connector with the correct amount of exposed copper. Once they find the problem connector, it can be exchanged for a new one.

e195 – Critical

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

As this error can drain your thermostat’s battery, the first step might be restoring enough power to determine if this specific error code is what you’re dealing with. You can detach the thermostat from its base and provide power with a USB cable. Assuming it displays error code 195, you should continue to visually inspect components like the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to find anything wrong with these components, it will probably be best to contact a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical error with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is experiencing more power than necessary. This may stem from the breaker box, an error from the control board or through a bad connection in the thermostat. The technician needs to cautiously inspect 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 might still stop 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 the absence of one can block your Nest from receiving enough power. You can check the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you need a Nest Power Connector.

With installation of a Nest Power Connector, you might notice error code E297 appear. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead be required 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 being delivered 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 take steps to prevent electrical damage, it’s suggested to turn the power off straightaway. You can then contact a professional technician with the appropriate experience diagnosing and resolving electrical damage.

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 may also be a problem with the wiring. After turning off the power to your HVAC system and thermostat, you can visually check the wires to make sure nothing is loose or damaged. If nothing seems to be out of place, it’s a good idea to get in touch with a local professional.