An immersion heater needs a thermostat control to save money and to stop
the water becoming dangerously hot. Set the temperature at 60°C (140°F).
If you have 'Economy 7' heating, you will have access to cheaper electricity
rates for seven hours a night, starting between midnight and 1am.
To gain maximum benefit of hot water, use a large 40-50 gallon cylinder
tank to store the water.
