[klausa]

FWIW "heats up instantly" and "has 1 degree temperature control" also describes modern gas heaters.

[cultureswitch]

I'm hoping you're right but I have yet to see a gas heater that actually heats up the water that cooled down in the pipes since the last usage so that you actually get warm water instantly.

[klausa]

I mean, it may be a couple seconds (like 5, not 30+), but ~every modern house in Japan has a heater like that.