Using a Nest thermostat is one of the most convenient ways to optimize the everyday schedule of your HVAC system. This smart thermostat can be taught your preferences and automatically make adjustments. But as you may 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 professional technician can use to present solutions that much quicker.

Let’s consider seven of the most likely error codes you may discover on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you could address it and the projected cost to do so. Remember that while the price will ultimately be dependent on the specific Nest model, you can count on paying around $75-$200 for repairs. This should include travel and labor costs as well as any specific hardware needed to complete repairs.

e298 – Critical

This critical error code is limited to the latest models of the Nest thermostat and appears 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 display until the problem is fixed.

Losing power to your Nest thermostat can be for a number of reasons. The wiring could have disconnected or become damaged, or a disconnection might have occurred further along in your home’s electrical system. This may be the circuit breaker, fuse box or system switch. A certified technician can check 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 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 make sure it’s not simply a software problem. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and start looking at connectors.

They’ll shut off the power and slowly look at each wire, ensuring they are fully placed into the connector with the proper amount of bare copper. When they find the problem connector, it can be swapped for a new one.

e195 – Critical

This critical error code can surface when the weather outside is severely hot. The HVAC system can shut down and stop giving power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will finally power down. In the event the breakers are on, you can search a couple of other places before calling a professional technician.

Because this error can drain your thermostat’s battery, the first step might be supplying enough power to determine if this specific error code is what you’re facing. You can separate the thermostat from its base and deliver power through a USB cable. Assuming it reveals error code 195, you can continue to visually examine components like the wiring as well as your air conditioner’s air filter or drainage system. If you don’t uncover anything wrong with these components, it will likely be best to contact a pro.

e103 – Critical

Another critical error code, e103 indicates an electrical error with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is getting more power than necessary. This can stem from the breaker box, an error from the control board or thanks to a faulty connection in the thermostat. Your technician will meticulously inspect 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.

n260

Even though this error code isn’t critical, it might still stop you from using the Nest thermostat like normal. Error code n260 refers to the lack of a C wire or Nest Power Connector, as the absence of 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 adjust the wiring itself if there is. If not, you need a Nest Power Connector.

Due to installation of a Nest Power Connector, you may notice error code E297 show up. This can be dealt with 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 originating from an overcurrent. If excessive 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 pop 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 contact a professional technician with the necessary experience identifying and resolving electrical damage.

e73 – Critical

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

This might be as simple 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 none of them are loose or damaged. If nothing appears to be out of place, it’s best to speak with a local professional.