Operating a Nest thermostat is one of the easiest ways to perfect the everyday schedule of your comfort system. This smart thermostat can recognize your preferences and automatically make adjustments. But as you can expect, it won’t work properly or at all if you see an error code on the display. The specific error code offers useful information about the underlying problem, something a professional technician can use to offer solutions that much quicker.
Listed below are seven of the most common error codes you could encounter 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 projected cost to do so. Keep in mind that while the costs will ultimately hinge on the exact Nest model, you can count on paying about $75-$200 for repairs. This should include travel and labor costs as well as any specific parts required to wrap up 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. Because this is a critical power error, the thermostat will switch to the backup battery system. The error message will remain on display until the problem is dealt with.
Losing power to your Nest thermostat can be for a number of reasons. The wiring may have disconnected or become damaged, or a disconnection may have appeared further along in your home's electrical system. This could be the circuit breaker, fuse box or system switch. A professional technician can examine electrical connections and wiring until they find 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 conduct a factory reset of your thermostat to make sure it’s not merely a software error. If that doesn’t work, they’ll review the wiring diagram of the thermostat and begin checking connectors.
They’ll disconnect the power and slowly look at each wire, seeing to it that they are fully inserted into the connector with the proper amount of bare copper. When they find the damaged connector, it can be exchanged for a new one.
e195 - Critical
This critical error code can appear when the weather outside is severely hot. The HVAC system can break down and stop sending power to your Nest thermostat. When this problem lingers, the backup battery in your thermostat drains and the thermostat will finally shut down. Presuming the breakers are on, you can check a few other places before consulting a professional technician.
As this error can consume your thermostat’s battery, the first step could be providing enough power to find out if this specific error code is what you’re dealing with. You can separate the thermostat from its base and provide power with a USB cable. Assuming it presents error code 195, you should continue to visually examine components such as the wiring as well as your air conditioner’s air filter or drainage system. If you don’t detect anything wrong with these components, it's maybe best to call a pro.
e103 - Critical
Another critical error code, e103 signifies an electrical malfunction 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 faulty connection in the thermostat. The technician can meticulously examine and test the Nest’s electrical system to understand where the power is surging or why the thermostat thinks there’s an overcurrent problem.
While this error code isn’t critical, it can still stop you from using the Nest thermostat like normal. Error code n260 pertains to the lack of a C wire or Nest Power Connector, as not having one can block your Nest from obtaining sufficient 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.
With installation of a Nest Power Connector, you will sometimes 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 have 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 that's the result of an overcurrent. If too much power is being delivered through the Nest’s wiring, it can damage internal components and could even be a fire hazard. If you see this error code show up on your Nest thermostat and want to take steps to prevent electrical damage, it’s recommended to shut the power off as soon as possible. You can then contact a professional technician with the proper experience diagnosing and fixing electrical problems.
e73 - Critical
When your thermostat displays error code e73, it signifies that the Rc wire is not receiving power. This may be as straightforward as the breaker being shut off, but it can also be something 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 time to contact a local professional.