THE GREAT DEBATE

Does turning the geyser off save energy?

This is a tricky question to answer, mostly because every household has different wateruse patterns, and geysers vary in terms of age, quality, condition and insulation

If everything is working properly, your geyser will switch on and off several times a day as the thermostat tries to keep the temperature where you set it (no higher than 60 °C). Today’s geysers are well insulated, though, so the tank will lose little heat and switch on briefly and infrequently.

A geyser that’s off should only lose about 10°C in 24 hours, so it’s feasible to only have it on every other day if you’re light on hot water, but you’ll have to reheat the whole tank at some point. Gains and losses practically cancel out.

Best bet? Insulate everything well to avoid heat getting lost in the first place ( see page 16), and it’ll lose less heat and run less often. Switch it off if you’ll be away for more than a few days, and around dinnertime – this is when the power grid is under the most strain, so it helps there. Installing a timer will save you some hassle.