On Saturday, 15 February 2020 18:31:40 UTC, Max Demian wrote:
On 15/02/2020 17:49, tabbypurr wrote:
On Saturday, 15 February 2020 16:28:03 UTC, Clive Arthur 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. She'e on Economy 7, so its set for night time operation but being a small capacity it sometimes runs out of hot water in the afternoon.

Does anyone know of a simple button type switch I could fit for her which could be preset for say 2 hours (ON), so she can hit it (to boost the hot water) and forget it. I've already fitted a red indicator light in the hall but this does not solve the problem.

I've seen similar device for communal lighting but they only work for say 5 mins.


How about a button which turns the heater on only until the thermostat
switches?

Easily feasible of course, but does anyone make such a thing?

Relays/contactors aren't hard to find.

Put the relay coil in series with the load with a push button that
shunts the relay contacts. You switch it on with the button and the
current through the load keeps the contacts closed until the thermostat
cuts the current through the element.

Only downside of that setup is it takes all year to heat the tank
Put the coil across the load side & it'll work. I'd ensure that one of the stats is not bridged by the switch.


NT