As you know, in America we just have hot water. There is a special little faucet and it has an H on it and we turn it on and...voila! Hot water. I would think it would be silly for me to expect anything different here.
Oh, was I wrong. So wrong. A very possible conversation:
American: "Do you know why the hot water isn't working?"
Irish: "Did you turn on the emersion?"
I: "Well, you have to turn on the emersion to get the hot water."
I: "See, in the hot press (cabinet for us Americans), you turn on the emersion, give it 10 minutes and you're ready to go." But never put it on 'bath', if you put it on 'sink' that should be plenty of hot water for your shower."
A: "This makes no freaking sense."
And another very possible conversation:
A: "Ah, nice hot shower for the first 30 seconds - maybe next time I'll put it on bath."
I: "Did you turn off the emersion?"
I: "WHAT??!! NOOOOOOOO!"
To be fair, if the heater is on in the house (central heating = radiators in each room), the hot water will just naturally work. Naturally.