How to Fix E298 Nest ‘No power’ Code

Is your Nest thermostat showing the E298 ‘No power’ code? Don’t worry – we’ve got you covered. In this article, we’ll guide you through the process of troubleshooting and resolving the E298 Nest ‘No power’ code.

The E298 error on Nest thermostats can be caused by a number of issues, including incorrect thermostat wiring, a missing C-wire connection, a tripped circuit breaker, or a blown fuse. These problems can disrupt the flow of power to the thermostat, resulting in the E298 code.

In the following table, let’s look at some of the causes of e298 code on your Nest.

Causes of E298 Code on Nest thermostat

Possible Cause	Fix
Incorrect thermostat wiring	Properly rewire your thermostat
No C wire connect	Connect C wire
Tripped Circuit breaker	Reset breaker
Blown Fuse	Replace fuse

Tripped Breakers

The E298 Error is a power issue code and so you might want to ensure that your system is receiving power.

Take a look at the switches for both the air handler and the outdoor unit. If they are on but the system is not receiving power, check the circuit breaker and reset tripped breakers if there are any.

If breakers and switches appear to be turned on, you might also want to take a look at the thermostat wiring.

Incorrect thermostat wiring

The first thing you want to check when you have an e298 error on your thermostat is the wiring configuration. To check the wiring configuration on your thermostat

Go to Settings Nest settings—-> Equipment—–> Wiring info

There you will see the wires that are detected by the thermostat as in the image below;

Take a look at R and C, are they grey? Undetected wires appear in grey while detected ones have color.

In other words when wires appear grey it means they are not sending voltage to your thermostat.

In some cases wires can be connected but still not detectable., This is mostly caused by loose connections.

And if all the wires appear grey, ensure that the whole system is receiving power. You could have tripped breakers.

Troubleshooting incorrect thermostat wiring;

Start by turning off power to your HVAC system. You can use a switch or do it by tripping the circuit breaker.

Remove the thermostat from the wall by pulling away from its base.

Pull out each wire by pushing down the connector. Look at each wire and ensure that each wire is stripped well enough and exposed at least ⅓ inches.

Re-insert the wires into their respective connectors ensuring that they are fully seated in and have proper contact with thermostat terminals.

After you have inserted all the wires, put back into the thermostat to its base and turn on the power

Use your thermostat to go to equipment settings and see if the problem is fixed.

Your thermostat doesn’t have the C wire.

If the problem persists, check your thermostat for a C wire. If there is a C wire but it’s not connected, connect it to the C connector. In many cases, when there is no wire connected in the C connector, you can find an unused wire, that’s the wire that you need to connect.

PS: Make sure to connect this wire to the C terminal of the furnace.

If there is no C or unused wire then you’ll most likely need to install a nest power connector. Installing a power connector is much easier than running an extra wire from the thermostat to the air handler (that is what I have personally noticed)

A power connector turns 4 wires into 5 wire output. This means that it will output an extra wire for the C connector which should run to the thermostat.

Power connectors are available in main stores and you can cheaply get one online for as low as $25. If you have a zone controller for your system that’s where you are going to install it. Otherwise, install it at the air handler.

There are also more hacks for getting around the C wire problem. One such hack involves a technique of using the G-wire as a C wire. This is quick and will not cost you anything.

Instructions on using G wire as C wire on Nest

Step 1. While your thermostat is off the wall and you can see the wiring. Remove the wire from the G connector and insert it into the C connector.

Step 2. Go to the air handler and do some changes there too. Remove the G wire from the G terminal and insert it into the C terminal. But keep in mind, the fan won’t run when there is a call for cooling.

Step 3. To enable the fan to run when cooling is on, you need to put a jumper wire between the Y and the G terminal. So that when cooling is energized, the fan is too.

Blown Fuse

The function of fuses in HVAC systems is to protect electrical components from damage caused by overcurrent conditions. Meaning that fuses are prone to blow out when there are voltage surges or when one or more wires come into contact with each other.

If you are a DIY person, you can use a multimeter to test the resistances across the 5 amp fuses on the control board. Blown fuses can easily and cheaply be replaced to fix the problem at hand.

FAQ

How do I reset my Nest thermostat without power?

Press your thermostat ring and hold it down until the screen turns off (about 10 seconds). Then let go of the ring. Press and release the ring to turn it back on and complete the restart process.

How do I know if my Nest thermostat is getting power?

For the Nest thermostat, go to Settings > Equipment > Power Connector to run a Power Test, then confirm the status is detected in Power Info.

Final thoughts

In this article, we have discussed the various causes of the E298 ‘No power’ code on Nest thermostats, including incorrect thermostat wiring, a missing C-wire connection, a tripped circuit breaker, or a blown fuse.

We have also provided solutions for each cause, such as rewiring your thermostat, connecting a C wire, resetting tripped breakers, and replacing blown fuses.

Whenever you encounter this error, follow the troubleshooting steps provided in this article to resolve the issue and ensure your Nest thermostat is receiving power.

More nest codes here

How to Fix E298 Nest ‘No power’ Code