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 optimize the day-to-day schedule of your heating and cooling. This smart thermostat can learn your preferences and automatically make adjustments. But as you might expect, it won’t work well 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 offer solutions that much faster.

Let's consider seven of the most common error codes you may find on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you could solve it and the estimated cost to do so. Remember that while the costs will ultimately hinge on the specific Nest model, you can anticipate paying about $75-$200 for repairs. This should include travel and labor costs as well as any specific components required to finish repairs.

e298 - Critical

This critical error code is limited to the latest models of the Nest thermostat and is displayed when the power is disconnected from the system. As this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on the screen until the problem is resolved.

Losing power to your Nest thermostat can be for numerous reasons. The wiring could have disconnected or become damaged, or a disconnection might have happened further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A certified technician can inspect electrical connections and wiring until they find the source of the problem.

e294 - Critical

Critical error code e294 shows up 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 problem. If that doesn’t work, they’ll review the wiring diagram of the thermostat and start inspecting connectors.

They’ll shut off the power and slowly check each wire, seeing to it that they are fully placed into the connector with the correct amount of bare copper. When they pinpoint the damaged connector, it can be replaced for a new one.

e195 - Critical

This critical error code can show up when the weather outside is especially 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 depletes and the thermostat will finally shut down. In the event the breakers are on, you can search a few other places before contacting a professional technician.

As this error can deplete your thermostat’s battery, the first step could be providing enough power to find out if this specific error code is what you’re facing. You can detach the thermostat from its base and provide power with a USB cable. Assuming it presents error code 195, you may continue to visually inspect components including 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 likely be best to call a pro.

e103 - Critical

Another critical error code, e103 signifies an electrical problem with your Nest thermostat. More specifically, e103 may 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 thanks to a faulty connection in the thermostat. Your technician can meticulously investigate 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 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 missing one can block your Nest from getting adequate 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.

With installation of a Nest Power Connector, you may notice error code E297 appear. This can be remedied 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 excess power is being delivered using the Nest’s wiring, it may damage internal components and can even be a fire hazard. If you notice this error code pop up on your Nest thermostat and want to guard against electrical damage, it’s recommended to switch the power off straightaway. You can then contact a professional technician with the appropriate experience identifying and fixing electrical issues.

e73 - Critical

When your thermostat displays error code e73, it indicates that the Rc wire is not getting power. This could be as easy as the breaker being shut off, but it may also be a problem with the wiring. After switching off the power to your HVAC system and thermostat, you can visually check the wires to make sure they’re not loose or damaged. If nothing appears to be out of place, it’s a good idea to speak with a local professional.