On 16/02/2020 08:14, alan_m wrote:
On 14/02/2020 13:32, The Natural Philosopher wrote:
On 14/02/2020 13:08, simon mitchelmore wrote:
My friend is too scared to turn on the immersion heater during the
day because she is absent minded and only remembers its on a few days
later and so gets big bills.

Not from an immersion heater she wont.

Total heat loss from a decent cylinder is probably less than 50W

That's assuming no water is used during the day.

When it will be somewhat less.

The immersion heater
could kick in during non economy 7 periods.

which makes no difference to it's heat loss



--
€œThe fundamental cause of the trouble in the modern world today is that
the stupid are cocksure while the intelligent are full of doubt."

- Bertrand Russell