Using a Nest thermostat is one of the easiest ways to perfect the daily schedule of your heating and cooling. This smart thermostat can be taught your preferences and automatically make improvements. But as you might expect, it won’t work properly or at all if you see an error code appear. The exact error code provides useful information about the underlying problem, something a knowledgeable technician can use to provide solutions that much quicker.
Let's consider seven of the most frequent error codes you may discover on your Nest thermostat. We’ll walk you through the basics of each error code on top of how you can solve it and the approximate cost to do so. Remember that while the price will ultimately be dependent on the specific Nest model, you can count on paying about $75-$200 for repairs. This should include travel and labor costs as well as any specific components 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. Since this is a critical power error, the thermostat will switch 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 your electrical system. This could be the circuit breaker, fuse box or system switch. A certified technician can check 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, the technician should reconfigure the R wire. They’ll first conduct a factory reset of your thermostat to make sure it’s not just a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and begin checking connectors.
They’ll shut off the power and slowly look at each wire, making sure they are fully inserted into the connector with the correct amount of uncovered copper. Once they find the malfunctioning 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 break down and stop delivering power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat depletes and the thermostat will eventually turn off. Assuming the breakers are on, you can search a handful of other places before contacting a professional technician.
As this error can drain your thermostat’s battery, the first step could be providing enough power to figure out if this specific error code is what you’re working with. You can separate the thermostat from its base and deliver power by using a USB cable. In the event it reveals error code 195, you should continue to visually inspect components such as the wiring as well as your air conditioner’s air filter or drainage system. If you struggle to find anything wrong with these components, it will likely be best to contact a pro.
e103 - Critical
Another critical error code, e103 suggests 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 because of a bad connection in the thermostat. A technician will meticulously examine and test the Nest’s electrical system to understand where the power is surging or why the thermostat is convinced there’s an overcurrent problem.
While this error code isn’t critical, it could still prevent 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 not having one can block your Nest from receiving 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’ll need a Nest Power Connector.
During installation of a Nest Power Connector, you will sometimes notice error code E297 appear. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector has already been installed, you’ll instead be required to update the wiring info in the app from Settings -> Thermostat -> Wiring -> Update wiring.
e104 - Critical
Just 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 may damage internal components and could even be a fire hazard. If you notice this error code appear on your Nest thermostat and want to protect from electrical damage, it’s recommended to shut the power off as soon as you can. You can then get in touch with a professional technician with the proper experience diagnosing and fixing electrical problems.
e73 - Critical
When your thermostat displays error code e73, it means that the Rc wire is not getting power. This will sometimes be as straightforward as the breaker being switched off, but it could also be a problem with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually examine the wires to make sure they’re not loose or damaged. If nothing seems to be out of place, it’s time to contact a local professional.