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 perfect the daily schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make improvements. But as you might expect, it won’t work correctly or at all if you see an error code show up. The specific error code provides useful information about the underlying problem, something a knowledgeable technician can use to provide solutions that much quicker.

Here are seven of the most common error codes you might find on your Nest thermostat. We’ll explain the basics of each error code on top of how you might solve it and the approximate cost to do so. Remember that while the price will ultimately depend on the exact Nest model, you can expect to pay about $75-$200 for repairs. This should also cover travel and labor costs as well as any specific hardware required to complete repairs.

e298 - Critical

This critical error code is limited to new models of the Nest thermostat and shows up when the power is shut off. Because 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 resolved.

Losing power to your Nest thermostat can be for a number of reasons. The wiring could have disconnected or become damaged, or a disconnection may have appeared further along in your home's electrical system. This might be the circuit breaker, fuse box or system switch. A certified technician will examine electrical connections and wiring until they uncover 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 perform a factory reset of your thermostat to make sure it’s not merely a software issue. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start looking at connectors.

They’ll disconnect the power and progressively check each wire, ensuring they are fully placed into the connector with the proper amount of exposed copper. When they locate the problem connector, it can be replaced for a new one.

e195 - Critical

This critical error code can appear when the weather outside is especially hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will eventually shut down. Assuming the breakers are on, you can inspect a couple of other places before contacting a professional technician.

Since this error can consume your thermostat’s battery, the first step could be providing enough power to figure out if this specific error code is what you’re working with. You can separate the thermostat from its base and provide power through a USB cable. Assuming it presents error code 195, you can continue to visually inspect components including 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 likely be best to call a pro.

e103 - Critical

Another critical error code, e103 signifies an electrical issue with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is experiencing more power than necessary. This may stem from the breaker box, an error from the control board or through a bad connection in the thermostat. A technician will carefully investigate and test the Nest’s electrical system to determine 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 prevent you from using the Nest thermostat how you prefer to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining adequate power. You can check 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.

With installation of a Nest Power Connector, you might notice error code E297 appear. This can be remedied by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead have 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 stemming from an overcurrent. If excess power is transported through the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you see this error code show up on your Nest thermostat and want to guard against electrical damage, it’s a good idea to switch the power off as soon as possible. You can then get in touch with a professional technician with the necessary experience diagnosing and fixing electrical malfunctions.

e73 - Critical

When your thermostat displays error code e73, it indicates that the Rc wire is not getting power. This could be as simple as the breaker being switched off, but it may also be an issue with the wiring. After turning off the power to your HVAC system and thermostat, you can visually examine the wires to make sure nothing is loose or damaged. If nothing appears to be out of place, it’s a good idea to contact a local professional.