Using a Nest thermostat is one of the most convenient ways to improve the everyday schedule of your comfort system. This smart thermostat can learn your preferences and automatically make adjustments. But as you can expect, it won’t work correctly or at all if you see an error code show up. The precise error code offers useful information about the underlying problem, something a knowledgeable technician can use to provide solutions that much quicker.
Let's consider seven of the most common error codes you may encounter on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you can fix it and the approximate cost to do so. Keep in mind that while the costs will ultimately be dependent on the precise Nest model, you can anticipate paying around $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 new models of the Nest thermostat and appears when the power is detached 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 problem is fixed.
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 electrical system. This may be the circuit breaker, fuse box or system switch. A knowledgeable technician can examine electrical connections and wiring until they uncover the root of the problem.
e294 - Critical
Critical error code e294 shows up when your Nest thermostat’s wiring should 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 ensure it’s not just a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start looking at connectors.
They’ll shut off the power and slowly look at each wire, making sure they are fully inserted into the connector with the proper amount of uncovered copper. When they locate the damaged connector, it can be swapped for a new one.
e195 - Critical
This critical error code can appear when the weather outside is particularly hot. The HVAC system can break down and stop giving power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will eventually power down. Assuming the breakers are on, you can examine a handful of other places before consulting a professional technician.
Since this error can consume your thermostat’s battery, the first step might be supplying enough power to figure out if this specific error code is what you’re dealing with. You can detach the thermostat from its base and deliver power with a USB cable. In the event it reveals error code 195, you can 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 detect anything wrong with these components, it will probably 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 receiving 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. Your technician can meticulously examine and test the Nest’s electrical system to understand where the power is surging or why the thermostat thinks there’s an overcurrent problem.
Even though this error code isn’t critical, it may still prevent you from using the Nest thermostat like normal. Error code n260 concerns the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining sufficient 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 need a Nest Power Connector.
During installation of a Nest Power Connector, you will sometimes notice error code E297 show up. 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
Like error code e103, e104 is a critical error that's the result of an overcurrent. If too much power is being delivered using the Nest’s wiring, it could damage internal components and may even be a fire hazard. If you see this error code appear 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 get in touch with a professional technician with the necessary experience diagnosing and solving electrical malfunctions.
e73 - Critical
When your thermostat displays error code e73, it signifies that the Rc wire is not receiving power. This may be as straightforward as the breaker being shut off, but it could also be an issue with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure they’re not loose or damaged. If nothing looks to be out of place, it’s a good idea to get in touch with a local professional.