How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Operating a Nest thermostat is one of the best ways to optimize the daily schedule of your comfort system. This smart thermostat can be taught 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 appear. The precise error code supplies useful information about the root of the problem, something a trained technician can use to provide solutions that much sooner.

Here are seven of the most likely error codes you could discover on your Nest thermostat. We’ll explain the basics of each error code as well as how you might solve it and the projected cost to do so. Keep in mind that while the costs will ultimately depend on the precise Nest model, you can count on paying between $75-$200 for repairs. This should include travel and labor costs along with any specific parts needed to wrap up 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 may have disconnected or become damaged, or a disconnection may have occurred further along in your home's electrical system. This could 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, you’ll need the technician to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to make sure it’s not simply a software problem. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start inspecting connectors.

They’ll shut off the power and slowly look at each wire, seeing to it that they are fully inserted into the connector with the proper amount of uncovered copper. When they pinpoint the damaged connector, it can be swapped for a new one.

e195 - Critical

This critical error code can surface when the weather outside is severely hot. The HVAC system can fail and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will finally shut down. Assuming the breakers are on, you can search a handful of other places before consulting a professional technician.

Since this error can drain your thermostat’s battery, the first step may be supplying enough power to determine if this specific error code is what you’re working with. You can disconnect the thermostat from its base and supply power with a USB cable. Assuming it presents error code 195, you should continue to visually examine components such as the wiring as well as your air conditioner’s air filter or drainage system. If you don’t detect anything wrong with these components, it's maybe best to get in touch with a pro.

e103 - Critical

Another critical error code, e103 indicates an electrical error with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is receiving more power than needed. This can stem from the breaker box, an error from the control board or thanks to a defective connection in the thermostat. The technician can carefully inspect and test the Nest’s electrical system to determine where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

Although this error code isn’t critical, it can 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 receiving adequate 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 need a Nest Power Connector.

With installation of a Nest Power Connector, you might notice error code E297 appear. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been 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 stemming from an overcurrent. If excess power is sent through the Nest’s wiring, it can damage internal components and could even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to protect from electrical damage, it’s a good idea to switch the power off as soon as possible. You can then get a hold of a professional technician with the proper experience detecting and solving electrical damage.

e73 - Critical

When your thermostat displays error code e73, it indicates that the Rc wire is not getting power. This will sometimes be as easy as the breaker being turned off, but it could also be a problem with the wiring. After turning off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure none of them are loose or damaged. If nothing seems to be out of place, it’s best to speak with a local professional.