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 heating and cooling. This smart thermostat can be taught your preferences and automatically make improvements. But as you can expect, it won’t work correctly or at all if you see an error code on the display. The specific error code offers useful information about the root of the problem, something a knowledgeable technician can use to offer solutions that much quicker.

Listed below are seven of the most frequent error codes you may encounter on your Nest thermostat. We’ll explain the basics of each error code along with how you might address it and the projected cost to do so. Don't forget that while the price will ultimately depend on the exact Nest model, you can expect to pay around $75-$200 for repairs. This should also cover travel and labor costs as well as any specific hardware necessary to complete repairs.

e298 - Critical

This critical error code is limited to new models of the Nest thermostat and appears when the power is disconnected from the system. 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 could have occurred further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician should inspect electrical connections and wiring until they locate the root of the problem.

e294 - Critical

Critical error code e294 appears when your Nest thermostat’s wiring should 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 merely a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin looking at connectors.

They’ll disconnect the power and slowly inspect each wire, seeing to it that they are fully attached into the connector with the correct amount of exposed copper. After they find the problem 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 shut down and stop sending power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat depletes and the thermostat will eventually turn off. In the event the breakers are on, you can search a few other places before contacting a professional technician.

Since this error can consume your thermostat’s battery, the first step could be supplying enough power to determine if this specific error code is what you’re dealing with. You can detach the thermostat from its base and supply power by using a USB cable. Assuming it presents error code 195, you can continue to visually check components such as the wiring as well as your air conditioner’s air filter or drainage system. If you don’t uncover anything wrong with these components, it's maybe best to get in touch with 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 what is safe and normal. This can stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. A technician needs to cautiously inspect and test the Nest’s electrical system to figure out where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

Although this error code isn’t critical, it could 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 enough 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 need a Nest Power Connector.

Due to installation of a Nest Power Connector, you may notice error code E297 be displayed. This can be remedied 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 excessive power is transported through the Nest’s wiring, it may damage internal components and can even be a fire hazard. If you see this error code appear on your Nest thermostat and want to take steps to prevent electrical damage, it’s a good idea to turn the power off as soon as possible. You can then get a hold of a professional technician with the necessary experience detecting and solving electrical damage.

e73 - Critical

When your thermostat displays error code e73, it means that the Rc wire is not getting power. This may be as simple as the breaker being shut off, but it could also be an issue 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 appears to be out of place, it’s best to get in touch with a local professional.