How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Operating a Nest thermostat is one of the most convenient ways to perfect the everyday schedule of your heating and cooling. This smart thermostat can recognize 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 show up. The precise error code supplies useful information about the underlying problem, something a trained technician can use to provide solutions that much quicker.

Here are seven of the most common error codes you may discover on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you might fix it and the projected cost to do so. Remember that while the price 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 along with any specific components needed to finish 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. Because this is a critical power error, the thermostat will change to the backup battery system. The error message will continue to be displayed until the issue is resolved.

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

e294 - Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first complete a factory reset of your thermostat to ensure 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 look at each wire, ensuring 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 especially hot. The HVAC system can shut down and stop delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will eventually shut down. Assuming the breakers are on, you can search a few other places before consulting a professional technician.

Since this error can drain your thermostat’s battery, the first step might be providing enough power to find out if this specific error code is what you’re facing. You can disconnect the thermostat from its base and deliver power with a USB cable. Assuming it displays 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 find anything wrong with these components, it will probably be best to call a pro.

e103 - Critical

Another critical error code, e103 indicates an electrical error with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is getting more power than necessary. This may stem from the breaker box, an error from the control board or through a faulty connection in the thermostat. A technician can meticulously investigate and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

Although this error code isn’t critical, it could still keep 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 missing 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 adjust the wiring itself if there is. If not, you can get a Nest Power Connector.

Due to installation of a Nest Power Connector, you will sometimes notice error code E297 be displayed. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead need 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 through the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you notice this error code show up on your Nest thermostat and want to protect from electrical damage, it’s recommended to turn the power off as soon as possible. You can then contact a professional technician with the appropriate experience identifying and solving electrical problems.

e73 - Critical

When your thermostat displays error code e73, it signifies that the Rc wire is not receiving power. This may be as easy as the breaker being turned off, but it can also be something with the wiring. After shutting 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 seems to be out of place, it’s a good idea to contact a local professional.