Operating a Nest thermostat is one of the best ways to perfect the daily schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make improvements. But as you can expect, it won’t work well or at all if you see an error code show up. The specific error code offers useful information about the source of the problem, something a professional technician can use to provide solutions that much sooner.
Here are seven of the most frequent error codes you might discover on your Nest thermostat. We’ll explain the basics of each error code along with how you could solve 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 also cover travel and labor costs along with any specific parts necessary to wrap up repairs.
e298 - Critical
This critical error code is limited to the latest models of the Nest thermostat and appears 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 the screen until the issue is resolved.
Losing power to your Nest thermostat can be for a number of reasons. The wiring may have disconnected or become damaged, or a disconnection could have appeared further along in the electrical system. This might be the circuit breaker, fuse box or system switch. A knowledgeable technician should check electrical connections and wiring until they find the root 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 perform 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 looking at connectors.
They’ll detach the power and progressively inspect each wire, seeing to it that they are fully attached into the connector with the correct amount of bare copper. After they find the problem connector, it can be replaced for a new one.
e195 - Critical
This critical error code can appear when the weather outside is severely hot. The HVAC system can break down and stop giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat depletes and the thermostat will eventually power down. Presuming the breakers are on, you can examine a few other places before consulting a professional technician.
Because this error can drain 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 disconnect the thermostat from its base and supply power by using a USB cable. In the event it reveals error code 195, you can continue to visually inspect 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 call a pro.
e103 - Critical
Another critical error code, e103 indicates an electrical malfunction with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is getting more power than needed. This may stem from the breaker box, an error from the control board or because of a faulty connection in the thermostat. A technician needs to carefully inspect and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes there’s an overcurrent problem.
Even though this error code isn’t critical, it could still stop you from using the Nest thermostat like normal. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from getting sufficient power. You can inspect the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you can get a Nest Power Connector.
During installation of a Nest Power Connector, you will sometimes notice error code E297 be displayed. This can be remedied 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
Similar to error code e103, e104 is a critical error that's the result of an overcurrent. If excess power is being delivered using the Nest’s wiring, it can damage internal components and may even be a fire hazard. If you see this error code pop up on your Nest thermostat and want to protect from electrical damage, it’s suggested to turn the power off as soon as you can. You can then contact a professional technician with the appropriate experience detecting and resolving 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 switched off, but it may also be a problem 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 appears to be out of place, it’s time to speak with a local professional.