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 learn your preferences and automatically make improvements. But as you may 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 root of the problem, something a knowledgeable technician can use to offer solutions that much faster.
Let's consider seven of the most common error codes you might encounter on your Nest thermostat. We’ll walk you through the basics of each error code along with how you might solve it and the estimated cost to do so. Don't forget that while the price will ultimately be dependent on the precise Nest model, you can anticipate paying around $75-$200 for repairs. This should also cover travel and labor costs as well as any specific hardware required to wrap up repairs.
e298 - Critical
This critical error code is limited to new models of the Nest thermostat and appears 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 remain on the screen until the issue is fixed.
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 knowledgeable technician will check electrical connections and wiring until they locate the root of the problem.
e294 - Critical
Critical error code e294 is displayed when your Nest thermostat’s wiring should be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first complete 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 inspecting connectors.
They’ll disconnect the power and gradually check each wire, seeing to it that they are fully inserted into the connector with the proper amount of exposed copper. Once they locate the malfunctioning connector, it can be swapped for a new one.
e195 - Critical
This critical error code can appear when the weather outside is severely 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 inspect a couple of other places before contacting a professional technician.
Since this error can drain your thermostat’s battery, the first step may be providing enough power to determine if this specific error code is what you’re facing. You can detach the thermostat from its base and supply power by using a USB cable. In the event it reveals error code 195, you can continue to visually check 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 probably be best to contact a pro.
e103 - Critical
Another critical error code, e103 indicates an electrical problem with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is getting more power than what is safe and normal. 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 inspect and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes there’s an overcurrent problem.
Although this error code isn’t critical, it could still stop you from using the Nest thermostat like normal. Error code n260 concerns the lack of a C wire or Nest Power Connector, as missing one can block your Nest from receiving sufficient 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’ll need a Nest Power Connector.
With installation of a Nest Power Connector, you may notice error code E297 show up. This can be dealt with 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
Just like error code e103, e104 is a critical error stemming from an overcurrent. If excess power is being delivered inside the Nest’s wiring, it could damage internal components and could even be a fire hazard. If you see this error code appear on your Nest thermostat and want to guard against electrical damage, it’s a good idea to turn the power off as soon as possible. You can then get in touch with a professional technician with the appropriate experience detecting and solving electrical damage.
e73 - Critical
When your thermostat displays error code e73, it signifies that the Rc wire is not getting power. This might be as straightforward as the breaker being switched off, but it may also be something with the wiring. After turning 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.