[stevehawk]

Tankless heaters seem like the biggest over promise household tech I can recall in the last decade or two. I have not found over that I would even come close to breaking even on when replacing either of the water heaters in my house.

[ed_balls]

Tankless heaters heaters are great if you live in a small flat or don't use it extensively (living alone, half of the time taking the shower at the gym).

Currently, in my flat there is only district heating which is way cheaper (lower cost, no maintenance). It's really great, should be the default in high density areas.