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 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 show up. The exact error code supplies useful information about the root of the problem, something a trained technician can use to offer solutions that much faster.

Let's consider seven of the most likely error codes you might encounter on your Nest thermostat. We’ll review the basics of each error code as well as how you could fix it and the approximate cost to do so. Keep in mind that while the costs will ultimately depend on the specific Nest model, you can expect to pay around $75-$200 for repairs. This should also cover travel and labor costs as well as any specific parts required to finish repairs.

e298 - Critical

This critical error code is limited to newer 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 dealt with.

Losing power to your Nest thermostat can be for a number of reasons. The wiring might have disconnected or become damaged, or a disconnection could have appeared further along in your electrical system. This might be the circuit breaker, fuse box or system switch. A certified technician can examine electrical connections and wiring until they find the root of the problem.

e294 - Critical

Critical error code e294 appears when your Nest thermostat’s wiring needs to be reconfigured. More specifically, the technician will need to 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 start looking at connectors.

They’ll disconnect the power and gradually inspect each wire, seeing to it that they are fully inserted into the connector with the correct amount of bare copper. After they locate the malfunctioning connector, it can be exchanged 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 giving power to your Nest thermostat. When this problem persists, the backup battery in your thermostat drains and the thermostat will eventually turn off. In the event the breakers are on, you can examine a couple of other places before contacting a professional technician.

Since 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 disconnect the thermostat from its base and provide power by using a USB cable. In the event it presents 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 can't find anything wrong with these components, it will likely be best to call a pro.

e103 - Critical

Another critical error code, e103 signifies an electrical issue with your Nest thermostat. More specifically, e103 can refer to an overcurrent problem, which means the wiring is receiving more power than needed. This can stem from the breaker box, an error from the control board or through a defective connection in the thermostat. A technician will carefully inspect and test the Nest’s electrical system to determine 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 may 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 not having one can block your Nest from obtaining enough power. You can inspect the Nest’s C connector for the presence of a C wire and modify the wiring itself if there is. If not, you can get a Nest Power Connector.

During 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 has already been installed, you’ll instead have 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 originating 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 see this error code appear on your Nest thermostat and want to take steps to prevent electrical damage, it’s suggested to shut the power off straightaway. You can then get a hold of a professional technician with the appropriate experience detecting and solving electrical problems.

e73 - Critical

When your thermostat displays error code e73, it indicates that the Rc wire is not receiving power. This will sometimes be as simple as the breaker being turned off, but it may also be a problem with the wiring. After shutting off the power to your HVAC system and thermostat, you can visually inspect the wires to make sure none of them are loose or damaged. If nothing appears to be out of place, it’s best to contact a local professional.