LG uses a two-letter system that is genuinely logical once you have seen it: the letter pair names the circuit, and the refrigerator codes prefix everything with ER. It is also the brand where reading the code most often saves a call-out entirely, because three of the most alarming displays are the machine working correctly — a child lock, a vent measurement and a self-test. Worth checking those before anything else.
Codes are not standardised between manufacturers, and they move between model years within one. Everything below is what these codes mean on the series named beside them — if your model is older or newer, treat this as a strong hint rather than a verdict, and send us a photo of the model plate when you book. That plate settles it, and it takes ten seconds.
Laundry shows the code where the remaining time normally sits. Refrigerators show it on the front panel, and some models only surface it after the door has been shut for a minute. If a washer display is showing nothing but the machine will not run, check whether the control panel is simply locked before assuming it is dead.