Operating a Nest thermostat is one of the most convenient ways to perfect the daily schedule of your HVAC system. This smart thermostat can be taught your preferences and automatically make adjustments. But as you might expect, it won’t work correctly or at all if you see an error code on the display. The precise error code provides useful information about the underlying problem, something a trained technician can use to offer solutions that much quicker.
Let's consider seven of the most likely error codes you may discover on your Nest thermostat. We’ll explain the basics of each error code along with how you might address it and the approximate cost to do so. Don't forget that while the price will ultimately hinge on the exact Nest model, you can expect to pay around $75-$200 for repairs. This should include things like travel and labor costs on top of 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 disconnected 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 display until the issue is resolved.
Losing power to your Nest thermostat can be for several reasons. The wiring may have disconnected or become damaged, or a disconnection might have appeared further along in your home's electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician will examine electrical connections and wiring until they locate the source of the problem.
e294 - Critical
Critical error code e294 is displayed when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician will need to reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to make sure it’s not just a software issue. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin looking at connectors.
They’ll detach the power and progressively look at each wire, seeing to it that they are fully inserted into the connector with the correct amount of uncovered copper. When they find the problem connector, it can be replaced for a new one.
e195 - Critical
This critical error code can surface when the weather outside is especially 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 eventually power down. Assuming the breakers are on, you can search a couple of other places before calling a professional technician.
Because this error can consume your thermostat’s battery, the first step could be providing 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 supply power with a USB cable. Assuming 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 likely be best to get in touch with a pro.
e103 - Critical
Another critical error code, e103 indicates 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 what is safe and normal. This may stem from the breaker box, an error from the control board or because of a bad connection in the thermostat. The technician will cautiously examine and test the Nest’s electrical system to determine where the power is surging or why the thermostat thinks there’s an overcurrent problem.
Although this error code isn’t critical, it can still keep 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 getting adequate power. You can inspect the Nest’s C connector for the presence of a C wire and adapt the wiring itself if there is. If not, you can get a Nest Power Connector.
Due to installation of a Nest Power Connector, you may notice error code E297 show up. 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
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 notice this error code appear on your Nest thermostat and want to take steps to prevent electrical damage, it’s recommended to turn the power off straightaway. You can then get a hold of a professional technician with the necessary experience detecting and solving electrical malfunctions.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not getting power. This could be as easy as the breaker being shut off, but it may also be an issue with the wiring. After switching 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.