Water heaters in Britain since around the 1980s would have a basic timer switch to turn them off/on up to twice a day. The old (pre-electronics) ones are easy

Water heaters in Britain since around the 1980s would have a basic timer switch to turn them off/on up to twice a day. The old (pre-electronics) ones are easy to understand — the heating/water comes on (in this case) at 10:00 and goes off at 16:30, then goes on again at 21:00 and off at 07:00: https://www.alamy.com/stock-photo-timer-control-for-hot-water-and-central-heating-control-unit-23980577.html https://www.alamy.com/stock-photo-timer-control-for-hot-wate...