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 heating and cooling. This smart thermostat can recognize your preferences and automatically make changes. But as you may expect, it won’t work properly or at all if you see an error code on the display. The specific error code supplies useful information about the source of the problem, something a trained technician can use to offer solutions that much sooner.

Let's consider seven of the most likely error codes you could discover on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you might address it and the approximate cost to do so. Keep in mind that while the price will ultimately hinge on the specific Nest model, you can expect to pay between $75-$200 for repairs. This should include things like travel and labor costs as well as any specific parts necessary to wrap up repairs.

e298 - Critical

This critical error code is limited to new models of the Nest thermostat and is displayed when the power is detached from the system. Since 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 numerous reasons. The wiring might have disconnected or become damaged, or a disconnection could have appeared further along in your home's electrical system. This might be the circuit breaker, fuse box or system switch. A trained technician should 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, 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 just 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 progressively inspect each wire, making sure they are fully placed into the connector with the proper amount of bare copper. After they locate the malfunctioning connector, it can be exchanged for a new one.

e195 - Critical

This critical error code can surface when the weather outside is particularly hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will eventually turn off. Presuming the breakers are on, you can inspect a handful of other places before contacting a professional technician.

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

e103 - Critical

Another critical error code, e103 signifies an electrical issue with your Nest thermostat. More specifically, e103 will 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 because of a faulty connection in the thermostat. A technician will carefully examine and test the Nest’s electrical system to figure out where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

While this error code isn’t critical, it can still stop you from using the Nest thermostat how you prefer 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 receiving adequate 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.

During installation of a Nest Power Connector, you may 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 have to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.

e104 - Critical

Just like error code e103, e104 is a critical error originating from an overcurrent. If too much power is being delivered through the Nest’s wiring, it could damage internal components and can 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 suggested to shut the power off as soon as you can. You can then get in touch with a professional technician with the appropriate experience detecting and solving electrical malfunctions.

e73 - Critical

When your thermostat displays error code e73, it indicates that the Rc wire is not receiving power. This may be as easy as the breaker being turned off, but it could 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 they’re not loose or damaged. If nothing seems to be out of place, it’s time to contact a local professional.