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 can expect, it won’t work properly or at all if you see an error code appear. The specific error code supplies useful information about the root of the problem, something a knowledgeable technician can use to offer solutions that much sooner.
Here are seven of the most likely error codes you may encounter on your Nest thermostat. We’ll review the basics of each error code along with how you can fix it and the projected cost to do so. Remember that while the price will ultimately be dependent on the precise Nest model, you can expect to pay about $75-$200 for repairs. This should include things like travel and labor costs on top of any specific parts needed to complete repairs.
e298 - Critical
This critical error code is limited to newer models of the Nest thermostat and shows up 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 the screen until the issue is resolved.
Losing power to your Nest thermostat can be for several reasons. The wiring could have disconnected or become damaged, or a disconnection may have occurred further along in the electrical system. This might be the circuit breaker, fuse box or system switch. A professional 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, the technician will need to reconfigure the R wire. They’ll first perform a factory reset of your thermostat to make sure it’s not merely a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin looking at connectors.
They’ll shut off the power and progressively check each wire, seeing to it that they are fully attached into the connector with the correct amount of bare copper. When they find the damaged connector, it can be swapped for a new one.
e195 - Critical
This critical error code can appear when the weather outside is especially hot. The HVAC system can fail and stop delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will eventually shut down. Presuming the breakers are on, you can examine a couple of other places before contacting a professional technician.
Because this error can consume your thermostat’s battery, the first step may be providing enough power to determine if this specific error code is what you’re facing. You can separate the thermostat from its base and supply power with a USB cable. In the event it reveals 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 can't detect anything wrong with these components, it will likely be best to contact a pro.
e103 - Critical
Another critical error code, e103 signifies an electrical issue 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 thanks to a faulty connection in the thermostat. The technician will cautiously investigate and test the Nest’s electrical system to figure out where the power is surging or why the thermostat thinks there’s an overcurrent problem.
Even though this error code isn’t critical, it can 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 receiving adequate power. You can examine the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you’ll need a Nest Power Connector.
With installation of a Nest Power Connector, you will sometimes notice error code E297 be displayed. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead have 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 originating from an overcurrent. If excess power is transported using the Nest’s wiring, it can damage internal components and may even be a fire hazard. If you see this error code show up on your Nest thermostat and want to guard against electrical damage, it’s suggested to shut the power off as soon as possible. You can then get a hold of a professional technician with the appropriate experience detecting and solving electrical issues.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not receiving power. This could be as easy as the breaker being shut off, but it may also be something 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 seems to be out of place, it’s a good idea to contact a local professional.