How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Using a Nest thermostat is one of the easiest ways to perfect the everyday schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make improvements. But as you can expect, it won’t work properly or at all if you see an error code on the display. The precise error code supplies useful information about the source of the problem, something a trained technician can use to provide solutions that much faster.

Let's consider seven of the most common error codes you could discover on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you might address it and the projected cost to do so. Keep in mind that while the costs will ultimately depend on the specific Nest model, you can expect to pay between $75-$200 for repairs. This should also cover travel and labor costs as well as any specific components needed to complete repairs.

e298 - Critical

This critical error code is limited to the latest models of the Nest thermostat and is displayed when the power is shut off. Because this is a critical power error, the thermostat will switch to the backup battery system. The error message will continue to be displayed until the problem is dealt with.

Losing power to your Nest thermostat can be for several reasons. The wiring might have disconnected or become damaged, or a disconnection may have occurred further along in your home's electrical system. This may be the circuit breaker, fuse box or system switch. A professional technician will 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 will need to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not simply a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin looking at connectors.

They’ll disconnect the power and gradually inspect each wire, seeing to it that they are fully inserted into the connector with the proper amount of uncovered copper. Once they find the damaged 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 break down and stop giving power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will eventually shut down. In the event the breakers are on, you can check a handful of other places before calling a professional technician.

Because this error can drain your thermostat’s battery, the first step may be restoring enough power to figure out if this specific error code is what you’re facing. You can separate the thermostat from its base and supply power with 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 don’t uncover anything wrong with these components, it's maybe best to contact a pro.

e103 - Critical

Another critical error code, e103 suggests 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 what is safe and normal. This can stem from the breaker box, an error from the control board or through a bad connection in the thermostat. A technician should meticulously examine 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

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 concerns the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining enough power. You can check the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you can get a Nest Power Connector.

During 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 has already been installed, you’ll instead need 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 excessive power is sent using the Nest’s wiring, it may damage internal components and can even be a fire hazard. If you see this error code appear on your Nest thermostat and want to protect from electrical damage, it’s recommended to turn the power off as soon as you can. 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 indicates that the Rc wire is not getting power. This might be as easy as the breaker being shut off, but it can also be an issue with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure nothing is loose or damaged. If nothing appears to be out of place, it’s time to get in touch with a local professional.