Installing a Nest thermostat is one of the easiest ways to improve the everyday schedule of your HVAC system. This smart thermostat can learn your preferences and automatically make adjustments. But as you can expect, it won’t work properly or at all if you see an error code on the display. The specific error code offers useful information about the underlying problem, something a knowledgeable technician can use to present solutions that much quicker.

Let’s consider seven of the most common error codes you might discover on your Nest thermostat. We’ll explain the basics of each error code on top of how you could fix it and the approximate cost to do so. Don’t forget that while the costs will ultimately depend on the specific Nest model, you can anticipate paying around $75-$200 for repairs. This should include travel and labor costs on top of any specific hardware needed to complete repairs.

e298 – Critical

This critical error code is limited to newer models of the Nest thermostat and appears when the power is shut off. Because 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 could have disconnected or become damaged, or a disconnection may have occurred further along in your electrical system. This might be the circuit breaker, fuse box or system switch. A trained technician should check electrical connections and wiring until they uncover 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 make sure it’s not merely a software issue. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin inspecting connectors.

They’ll disconnect the power and progressively look at each wire, seeing to it that they are fully inserted into the connector with the proper amount of exposed copper. Once 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 especially 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 eventually turn off. Assuming the breakers are on, you can inspect a couple of other places before calling a professional technician.

Because this error can consume 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 separate the thermostat from its base and supply power through 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 struggle to detect anything wrong with these components, it will probably be best to get in touch with a pro.

e103 – Critical

Another critical error code, e103 suggests an electrical error with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is receiving more power than necessary. This will sometimes stem from the breaker box, an error from the control board or because of a defective connection in the thermostat. The technician should meticulously investigate and test the Nest’s electrical system to determine 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 could 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 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 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 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 stemming from an overcurrent. If excessive power is being delivered using the Nest’s wiring, it could damage internal components and may even be a fire hazard. If you notice this error code pop up on your Nest thermostat and want to protect from electrical damage, it’s suggested to switch the power off straightaway. You can then contact a professional technician with the appropriate experience identifying and solving electrical problems.

e73 – Critical

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

This could be as simple as the breaker being turned off, but it may also be something with the wiring. After shutting 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 a good idea to speak with a local professional.