Operating a Nest thermostat is one of the most convenient ways to optimize the day-to-day schedule of your HVAC system. This smart thermostat can learn your preferences and automatically make changes. But as you may 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 underlying problem, something a knowledgeable technician can use to provide solutions that much quicker.

Listed below are seven of the most likely error codes you might encounter on your Nest thermostat. We’ll explain the basics of each error code as well as 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 anticipate paying between $75-$200 for repairs. This should include things like travel and labor costs on top of any specific hardware necessary to finish repairs.

e298 – Critical

This critical error code is limited to newer 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 switch to the backup battery system. The error message will remain on display until the issue is fixed.

Losing power to your Nest thermostat can be for numerous reasons. The wiring could have disconnected or become damaged, or a disconnection might have appeared further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A knowledgeable technician should examine electrical connections and wiring until they find the source of the problem.

e294 – Critical

Critical error code e294 is displayed when your Nest thermostat’s wiring should be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first complete a factory reset of your thermostat to ensure it’s not just 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 slowly look at each wire, seeing to it that they are fully inserted into the connector with the correct amount of exposed copper. After they find the damaged connector, it can be replaced for a new one.

e195 – Critical

This critical error code can surface when the weather outside is particularly hot. The HVAC system can fail and stop giving power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will subsequently shut down. Presuming the breakers are on, you can check a couple of other places before contacting a professional technician.

Because this error can deplete your thermostat’s battery, the first step could be supplying enough power to find out if this specific error code is what you’re working with. You can detach the thermostat from its base and deliver power with a USB cable. If it displays error code 195, you should 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 probably be best to get in touch with 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 experiencing more power than needed. This will sometimes stem from the breaker box, an error from the control board or thanks to a defective connection in the thermostat. Your technician will meticulously inspect and test the Nest’s electrical system to figure out where the power is surging or why the thermostat is convinced there’s an overcurrent problem.

n260

While this error code isn’t critical, it may still stop you from using the Nest thermostat how you want to. Error code n260 concerns the lack of a C wire or Nest Power Connector, as missing one can block your Nest from obtaining adequate power. You can check the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you need a Nest Power Connector.

During installation of a Nest Power Connector, you might notice error code E297 appear. This can be remedied 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

Similar to error code e103, e104 is a critical error stemming from an overcurrent. If too much power is being delivered using the Nest’s wiring, it could damage internal components and can even be a fire hazard. If you notice this error code show up on your Nest thermostat and want to guard against electrical damage, it’s a good idea to turn the power off straightaway. You can then get a hold of a professional technician with the proper experience diagnosing and fixing electrical malfunctions.

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 switched off, but it could also be something with the wiring. After turning 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 seems to be out of place, it’s time to speak with a local professional.