Operating a Nest thermostat is one of the best 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 may expect, it won’t work correctly or at all if you see an error code on the display. The exact error code offers useful information about the root of the problem, something a professional technician can use to present solutions that much sooner.
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 on top of how you could address it and the projected cost to do so. Don't forget that while the price will ultimately be dependent on the specific Nest model, you can expect to pay between $75-$200 for repairs. This should include things like travel and labor costs on top of any specific hardware needed to finish repairs.
e298 - Critical
This critical error code is limited to the latest models of the Nest thermostat and shows up when the power is detached 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 display until the issue is dealt with.
Losing power to your Nest thermostat can be for a number of reasons. The wiring might have disconnected or become damaged, or a disconnection may have appeared further along in your electrical system. This could be the circuit breaker, fuse box or system switch. A trained technician can inspect electrical connections and wiring until they locate the root of the problem.
e294 - Critical
Critical error code e294 shows up when your Nest thermostat’s wiring has to be reconfigured. More specifically, you’ll need the technician to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to make sure it’s not just a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin inspecting connectors.
They’ll shut off the power and progressively look at each wire, seeing to it that they are fully placed into the connector with the proper amount of bare copper. When they find the malfunctioning 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 giving power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will subsequently turn off. In the event the breakers are on, you can check a couple of other places before calling a professional technician.
As this error can drain your thermostat’s battery, the first step may be supplying enough power to find out if this specific error code is what you’re working with. You can separate the thermostat from its base and deliver power through a USB cable. If it reveals error code 195, you may 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 detect anything wrong with these components, it will likely be best to contact a pro.
e103 - Critical
Another critical error code, e103 suggests an electrical issue with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is experiencing more power than needed. This will sometimes stem from the breaker box, an error from the control board or because of a bad connection in the thermostat. Your technician will carefully investigate 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 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 adequate power. You can examine 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 will sometimes notice error code E297 be displayed. This can be resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been 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 originating from an overcurrent. If excess power is being delivered inside the Nest’s wiring, it can damage internal components and may 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 contact a professional technician with the proper experience identifying and resolving electrical issues.
e73 - Critical
When your thermostat displays error code e73, it indicates that the Rc wire is not receiving power. This will sometimes be as straightforward as the breaker being turned off, but it can also be something 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 time to contact a local professional.