Using a Nest thermostat is one of the best ways to optimize the day-to-day schedule of your comfort system. This smart thermostat can recognize 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 appear. The specific error code provides useful information about the root of the problem, something a trained technician can use to provide solutions that much quicker.
Let's consider seven of the most common error codes you could encounter on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you could fix it and the projected cost to do so. Don't forget that while the price will ultimately hinge on the precise Nest model, you can expect to pay about $75-$200 for repairs. This should include travel and labor costs as well as any specific hardware needed to complete repairs.
e298 - Critical
This critical error code is limited to newer models of the Nest thermostat and shows up when the power is disconnected from the system. Because this is a critical power error, the thermostat will swap to the backup battery system. The error message will remain on the screen until the issue is resolved.
Losing power to your Nest thermostat can be for several reasons. The wiring may have disconnected or become damaged, or a disconnection might have happened further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A trained technician can inspect electrical connections and wiring until they find the root of the problem.
e294 - Critical
Critical error code e294 shows up 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 make sure it’s not merely a software issue. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin checking connectors.
They’ll shut off the power and gradually check each wire, making sure they are fully placed into the connector with the correct amount of bare copper. Once they find the malfunctioning connector, it can be exchanged for a new one.
e195 - Critical
This critical error code can show up 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 finally shut down. Assuming the breakers are on, you can check a few other places before calling a professional technician.
Since this error can deplete your thermostat’s battery, the first step might be providing enough power to figure out if this specific error code is what you’re facing. You can separate the thermostat from its base and provide power through a USB cable. If it reveals error code 195, you should continue to visually inspect components including the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to detect anything wrong with these components, it will probably be best to contact a pro.
e103 - Critical
Another critical error code, e103 indicates 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 may stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. Your technician needs to carefully 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.
While this error code isn’t critical, it may still stop you from using the Nest thermostat how you want to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as the absence of 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 modify the wiring itself if there is. If not, you can get a Nest Power Connector.
During installation of a Nest Power Connector, you might 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 that's the result of an overcurrent. If excess power is sent inside the Nest’s wiring, it may 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 recommended to shut the power off as soon as possible. You can then get a hold of a professional technician with the appropriate experience diagnosing and resolving electrical problems.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not receiving power. This could be as simple as the breaker being shut off, but it can also be an issue with the wiring. After switching 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 looks to be out of place, it’s best to contact a local professional.