How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Operating a Nest thermostat is one of the easiest ways to perfect the day-to-day schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make adjustments. But as you can expect, it won’t work well or at all if you see an error code on the display. The precise error code provides useful information about the root of the problem, something a professional technician can use to offer solutions that much quicker.

Here are seven of the most frequent error codes you could find on your Nest thermostat. We’ll review the basics of each error code along with how you can address it and the projected cost to do so. Remember that while the costs will ultimately depend 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 needed to finish repairs.

e298 - Critical

This critical error code is limited to newer models of the Nest thermostat and appears when the power is detached from the system. Because this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on display until the issue is resolved.

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

e294 - Critical

Critical error code e294 shows up when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first complete a factory reset of your thermostat to make sure it’s not simply a software error. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin looking at connectors.

They’ll shut off the power and gradually inspect each wire, seeing to it that they are fully attached into the connector with the proper amount of uncovered copper. After they locate 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 severely hot. The HVAC system can break down and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will subsequently power down. Assuming the breakers are on, you can check a couple of other places before contacting a professional technician.

Because this error can consume your thermostat’s battery, the first step might be supplying enough power to figure out if this specific error code is what you’re dealing with. You can disconnect the thermostat from its base and supply power through a USB cable. In the event 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 struggle to detect anything wrong with these components, it will probably be best to contact a pro.

e103 - Critical

Another critical error code, e103 signifies an electrical problem with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is receiving more power than necessary. This may stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. A technician will cautiously inspect 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

Although this error code isn’t critical, it might 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 not having one can block your Nest from obtaining sufficient power. You can inspect 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.

With installation of a Nest Power Connector, you might notice error code E297 appear. This can be resolved 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

Like error code e103, e104 is a critical error stemming from an overcurrent. If too much power is sent inside the Nest’s wiring, it could damage internal components and could even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to take steps to prevent electrical damage, it’s a good idea to shut the power off straightaway. You can then contact a professional technician with the proper experience identifying and resolving electrical malfunctions.

e73 - Critical

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