Installing a Nest thermostat is one of the most convenient ways to improve the day-to-day schedule of your HVAC system. This smart thermostat can learn your preferences and automatically make improvements. But as you might expect, it won’t work correctly or at all if you see an error code on the display. The specific error code offers useful information about the source of the problem, something a knowledgeable technician can use to present solutions that much sooner.

Listed below are seven of the most common error codes you might find on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you might address it and the estimated cost to do so. Don’t forget that while the price will ultimately depend on the exact Nest model, you can anticipate paying around $75-$200 for repairs. This should also cover travel and labor costs on top of any specific components necessary to wrap up repairs.

e298 – Critical

This critical error code is limited to new models of the Nest thermostat and is displayed when the power is shut off. Since this is a critical power error, the thermostat will change to the backup battery system. The error message will remain on the screen 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 may have occurred further along in your electrical system. This may be the circuit breaker, fuse box or system switch. A professional technician can inspect 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 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 simply a software problem. If that doesn’t work, they’ll check the wiring diagram of the thermostat and start inspecting connectors.

They’ll shut off the power and progressively look at each wire, ensuring they are fully attached into the connector with the proper amount of bare copper. Once they locate the problem connector, it can be exchanged for a new one.

e195 – Critical

This critical error code can show up when the weather outside is severely hot. The HVAC system can break down and stop sending power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will eventually shut down. Assuming the breakers are on, you can check a few other places before consulting a professional technician.

Since this error can drain your thermostat’s battery, the first step may be providing enough power to find out if this specific error code is what you’re working with. You can separate the thermostat from its base and provide power through a USB cable. In the event it displays error code 195, you may continue to visually inspect components including the wiring as well as your air conditioner’s air filter or drainage system. If you don’t find anything wrong with these components, it will likely be best to call a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical problem with your Nest thermostat. More specifically, e103 may refer to an overcurrent problem, which means the wiring is experiencing 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 faulty connection in the thermostat. The technician needs to meticulously inspect and test the Nest’s electrical system to understand where the power is surging or why the thermostat thinks there’s an overcurrent problem.

n260

Although this error code isn’t critical, it might still prevent 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 obtaining enough power. You can check the Nest’s C connector for the presence of a C wire and adjust the wiring itself if there is. If not, you’ll need a Nest Power Connector.

Due to installation of a Nest Power Connector, you might notice error code E297 be displayed. This can be resolved 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

Just like error code e103, e104 is a critical error stemming from an overcurrent. If excessive power is transported through the Nest’s wiring, it can 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 suggested to switch the power off as soon as you can. You can then get in touch with a professional technician with the necessary experience detecting and fixing electrical damage.

e73 – Critical

When your thermostat displays error code e73, it signifies that the Rc wire is not getting power.

This could be as straightforward as the breaker being switched off, but it could also be a problem with the wiring. After switching 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 best to speak with a local professional.