On Sat, 01 Dec 2018 12:32:26 -0000, R D S wrote:

On 30/11/2018 15:05, Andy Bennet wrote:
On 29/11/2018 20:30, Bruce Farquhar wrote:
Those cheap Chinese water heaters which are simply two plates of
metal, one on live and one on neutral, how can they work? Because the
resistivity of tap water apparently varies from 2 to 200 ohm metres.
That's a range of 100 fold in possible power output. I assume the
resistivity changes due to impurities like lime in hard water areas?

Big Clive did a review of these a couple of years ago
https://www.youtube.com/watch?v=EViyccc2t9w


I can't believe I sat through that and nothing went bang.

Yes, explosions are much more fun.