How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Using a Nest thermostat is one of the best ways to perfect the day-to-day schedule of your comfort system. This smart thermostat can be taught your preferences and automatically make adjustments. But as you might expect, it won’t work correctly or at all if you see an error code on the display. The precise error code provides useful information about the source of the problem, something a trained technician can use to provide solutions that much sooner.

Listed below are seven of the most common error codes you might encounter on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you can solve it and the approximate cost to do so. Keep in mind that while the costs will ultimately hinge on the precise Nest model, you can anticipate paying around $75-$200 for repairs. This should also cover travel and labor costs as well as any specific hardware necessary to finish repairs.

e298 - Critical

This critical error code is limited to new models of the Nest thermostat and appears when the power is shut off. Since 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 dealt with.

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

e294 - Critical

Critical error code e294 appears when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to ensure it’s not simply a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start looking at connectors.

They’ll shut off the power and progressively look at each wire, seeing to it that they are fully inserted into the connector with the correct amount of uncovered copper. After they pinpoint 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 especially hot. The HVAC system can fail and stop giving power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will finally power down. In the event the breakers are on, you can inspect a handful of other places before calling a professional technician.

As this error can deplete your thermostat’s battery, the first step could be supplying enough power to figure out if this specific error code is what you’re facing. You can detach the thermostat from its base and supply power through a USB cable. Assuming it presents error code 195, you may continue to visually check components like the wiring as well as your air conditioner’s air filter or drainage system. If you can't find anything wrong with these components, it will likely be best to call a pro.

e103 - Critical

Another critical error code, e103 indicates an electrical error with your Nest thermostat. More specifically, e103 will 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 because of a faulty connection in the thermostat. A technician can carefully investigate and test the Nest’s electrical system to understand 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 keep you from using the Nest thermostat like normal. 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 adapt the wiring itself if there is. If not, you can get a Nest Power Connector.

Due to 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 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 inside the Nest’s wiring, it can damage internal components and could even be a fire hazard. If you see this error code show up on your Nest thermostat and want to protect from electrical damage, it’s suggested to switch the power off as soon as you can. You can then get a hold of a professional technician with the necessary experience identifying and resolving electrical damage.

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 turned off, but it could 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 nothing is loose or damaged. If nothing looks to be out of place, it’s best to get in touch with a local professional.