Operating a Nest thermostat is one of the best ways to optimize the day-to-day schedule of your HVAC system. This smart thermostat can recognize your preferences and automatically make adjustments. But as you may expect, it won’t work well or at all if you see an error code appear. The exact error code provides useful information about the underlying problem, something a trained technician can use to offer solutions that much faster.
Let's consider seven of the most frequent error codes you may find on your Nest thermostat. We’ll review the basics of each error code along with how you could solve it and the projected cost to do so. Remember that while the costs will ultimately hinge on the exact Nest model, you can expect to pay about $75-$200 for repairs. This should include travel and labor costs on top of any specific parts required to wrap up repairs.
e298 - Critical
This critical error code is limited to new models of the Nest thermostat and is displayed when the power is detached from the system. As this is a critical power error, the thermostat will swap 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 could have disconnected or become damaged, or a disconnection could have happened further along in your home's electrical system. This may be the circuit breaker, fuse box or system switch. A professional technician should examine electrical connections and wiring until they locate the source 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 conduct a factory reset of your thermostat to ensure it’s not merely a software error. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin looking at connectors.
They’ll shut off the power and gradually check each wire, making sure they are fully inserted into the connector with the correct amount of uncovered copper. Once they find the problem connector, it can be swapped for a new one.
e195 - Critical
This critical error code can surface when the weather outside is particularly hot. The HVAC system can break down and stop delivering power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will finally shut down. Assuming the breakers are on, you can check a couple of other places before calling a professional technician.
Since this error can consume your thermostat’s battery, the first step may be restoring enough power to determine if this specific error code is what you’re working with. You can separate the thermostat from its base and provide power by using a USB cable. Assuming it displays error code 195, you may continue to visually check components including 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 get in touch with a pro.
e103 - Critical
Another critical error code, e103 suggests an electrical error with your Nest thermostat. More specifically, e103 can 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 faulty connection in the thermostat. Your technician will cautiously examine and test the Nest’s electrical system to figure out where the power is surging or why the thermostat believes there’s an overcurrent problem.
Although this error code isn’t critical, it can still keep you from using the Nest thermostat how you prefer to. Error code n260 refers to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from getting enough power. You can check the Nest’s C connector for the presence of a C wire and adapt 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 resolved by updating your thermostat in Settings -> Software -> Update. If the Power Connector was already installed, you’ll instead need 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 stemming from an overcurrent. If too much power is being delivered inside the Nest’s wiring, it could damage internal components and may even be a fire hazard. If you notice this error code pop up on your Nest thermostat and want to guard against electrical damage, it’s recommended to switch the power off straightaway. You can then contact a professional technician with the necessary experience detecting and fixing electrical problems.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not receiving power. This will sometimes be as easy as the breaker being turned off, but it could also be something with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually inspect 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.