I got married at 22. So yes.
Know how to use the washing machine? Ds age 6yo can do that. He struggles on hanging it out on the line because of his size, but he has done it with a chair (and me wincing, but he was determined he would do that all on his own)
know where the fuses were? Ds does again. He also knows how to trip the switch, and how to reset the switches of tripped. Not totally sure dd2 (age 10yo) knows because she has no interest in it, but I think she would.
Know how to reset the boiler? Actually I do struggle with that one on our current boiler. There were no instructions when we moved it, and it does have a habit of resetting itself, and I always have to think hard about how to get it back.
know water has to be paid for? The dc do, simply because we moved to a house with a watermeter, so it was a big discussion at one point. Not sure I would have realised much before 21, we didn't pay until we moved into a house at 24yo, because the flats paid out of the flat fee which included things like external lighting, gardener, and water.
Know how to wash up? All three dc were doing that from the point they could stand safely on the chair to do it, so probably about 2yo. they thought it was a treat then. Now they can do it without the chair (except ds) it is a chore. 