I need your advice on LG air conditioner troubleshooting.

I assume you actually turned it on, and turned the temperature down.

I put that in the category of common sense.

You’d be surprised how many HVAC calls end with someone flipping a switch from heat to cool, in response to someone who said I set it to sixty and it still does not cool. Though the error code E2 means the indoor temperature sensor failed.

So if I get the E2 error, it is not the thermostat but the temperature the AC thinks things are.

You can check the wires to the control board, power cycle the unit to reboot the AC control board to see if that fixes it or try to replace the sensor.

And if none of that works, I have to replace the control board. For that much money, I might as well replace the AC.

For a window AC, I’d say yes. For a whole house air conditioner, the control board is several hundred when a replacement AC is several thousand.

What else should I look for?

If it tells you an error code of E1, the temperature sensor has failed. The trouble shooting of turning off power to the unit and replacing the sensor are the same as for the E2 error.

It is not refusing to work because it thinks the house is already cold. That’s not the error I’m getting, and the unit isn’t working right, sometimes not working at all.

The E3 error means that it is shut down because of an abnormal operation error. You can power cycle the control board or check the wiring, and sometimes it is fixed by replacing temperature sensors.

Replacing temperature sensors seems to be the standard solution.

That’s because it is the cheap one to try. However, you can get the E3 error because the fan blades are vibrating too much or stopped because the fan is broken, it cannot get enough air due to dirty filters –

Replacing the filters is something I probably need to do anyway.

You can get the error if the control panel is erroring out because it is damaged, whether shorted out after a lightening hit or moisture that seeped into the unit, or a wire harness is damaged by a squirrel chewing on it.

If a squirrel did that, I’d know it by the barbeque smell coming through the vents.

If you smell a burnt smell, it could be a wiring short or overheating motor or dirty unit carbonizing while it defrosts. And an overheating motor or condenser will turn off the unit too, so it does not get so hot the AC catches fire.

The only song of fire and ice I want in my house is the George Martin book, not a fire alarm while the frozen AC burns in the back yard.