How to Resolve These Seven Error Codes on Your Nest Thermostat

August 15, 2022

Operating a Nest thermostat is one of the easiest ways to improve the everyday schedule of your heating and cooling. This smart thermostat can learn your preferences and automatically make changes. But as you can expect, it won’t work well or at all if you see an error code appear. The precise error code provides useful information about the underlying problem, something a trained technician can use to offer solutions that much quicker.

Let's consider seven of the most common error codes you may encounter on your Nest thermostat. We’ll walk you through the basics of each error code as well as how you can address it and the projected cost to do so. Don't forget that while the price will ultimately hinge on the exact Nest model, you can expect to pay around $75-$200 for repairs. This should include things like travel and labor costs as well as any specific parts necessary to finish repairs.

e298 - Critical

This critical error code is limited to newer models of the Nest thermostat and is displayed when the power is shut off. 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 problem is dealt with.

Losing power to your Nest thermostat can be for numerous reasons. The wiring may have disconnected or become damaged, or a disconnection may have appeared further along in your home's electrical system. This may be the circuit breaker, fuse box or system switch. A trained technician will check electrical connections and wiring until they uncover the source of the problem.

e294 - Critical

Critical error code e294 appears when your Nest thermostat’s wiring should be reconfigured. More specifically, the technician should reconfigure the R wire. They’ll first perform a factory reset of your thermostat to ensure it’s not simply a software issue. If that doesn’t work, they’ll examine the wiring diagram of the thermostat and begin looking at connectors.

They’ll disconnect the power and gradually look at each wire, making sure they are fully inserted into the connector with the correct 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 show up when the weather outside is especially hot. The HVAC system can break down and stop sending power to your Nest thermostat. When this problem lasts, the backup battery in your thermostat drains and the thermostat will subsequently power down. Presuming the breakers are on, you can examine a couple of other places before consulting a professional technician.

As this error can drain your thermostat’s battery, the first step may be supplying enough power to figure out if this specific error code is what you’re facing. You can detach the thermostat from its base and deliver power by using a USB cable. If it displays error code 195, you may continue to visually check components such as 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 contact a pro.

e103 - Critical

Another critical error code, e103 signifies an electrical malfunction with your Nest thermostat. More specifically, e103 will refer to an overcurrent problem, which means the wiring is receiving more power than necessary. This may stem from the breaker box, an error from the control board or thanks to a bad connection in the thermostat. Your technician can meticulously investigate and test the Nest’s electrical system to understand where the power is surging or why the thermostat believes there’s an overcurrent problem.

n260

Even though this error code isn’t critical, it might still keep you from using the Nest thermostat like normal. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as the absence of one can block your Nest from receiving sufficient 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 will sometimes notice error code E297 appear. This can be dealt with by updating your thermostat in Settings -> Software -> Update. If the Power Connector is already installed, you’ll instead be required 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 being delivered inside the Nest’s wiring, it can damage internal components and can even be a fire hazard. If you see this error code show up on your Nest thermostat and want to protect from 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 detecting and fixing electrical issues.

e73 - Critical

When your thermostat displays error code e73, it signifies that the Rc wire is not getting power. This may be as simple as the breaker being turned off, but it can also be something with the wiring. After turning 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 get in touch with a local professional.