Comments by "Mikko Rantalainen" (@MikkoRantalainen) on "A simple water heater is more clever than it seems" video.

  1. A scandinavian manufacturer (Nibe) which manufactures water heaters, exhaust air heat pumps and similar stuff has computer controlled water heaters which run logic to heat the water only once per 2 weeks above 55 degrees celcius. (Of course, the cycle time is adjustable but that's the default if I remember correctly.) That's enough to kill any bacteria as long as your incoming water source is pure enough. At all other times, keeping the water a bit cooler will reduce energy usage. The hot water storage in our unit has 4 temperature sensors which monitor the amount of hot water.
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  2. There's probably also extra magic in front of the incoming water pipe inside that heater to reduce currents from the water flow. This is usually implemented by one or two extra metal plates.
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