Print Friendly and PDF

Switch off the geyser and save!

Eskom urges everyone to switch off their geysers to save electricity, but does this make any difference to the overall demand - and your monthly cost?

With thousands of geysers across the country running during the day and night, this places enormous strain on the electrical supply grid. Craig Berman from Saving Energy offers advice on this topic:

Switching off the geyser has a substantial impact on overall electricity demand.

In the average South African property the geyser accounts for around 40% to 60% of the total electricity used in a month. "When you have thousands of geysers running during the day and night, this places tremendous strain on the supply grid." says Craig. "This is the main reason for Eskom to frequently request consumers to install geyser timers - that control the geyser’s operating times and be more efficient - as this also ensures that the geyser is off during peak demand periods."

Switching the geyser on and off saves energy

A conventional hot water geyser operates by using electricity to heat water to the set temperature of the thermostat. The water cools the thermostat then switches the element back on to reheat the water. This cycle can happen 15 to 30 times per day. Craig stated that, "Most people don’t need hot water throughout the day and a lot of electricity is wasted when the geyser is heating water when not required in the home."

"A  standard 150 litre geyser needs about an hour to heat water to the set temperature from cold. So switching the geyser off when hot water is not required and switching it on an hour or so before hot water is needed will cut the amount of electricity used." Craig says. "Allowing the geyser to run for 24 hours results in high electricity wastage - especially during winter -, and more so if the geyser does not have a geyser blanket to prevent the additional heat loss," he says.





Switching a geyser on and off will not damage the thermostat

A family of four that needs hot water in the morning and evening for showering or bathing, and only minimal hot water during the day, doesn’t need to have their geyser running continuously. "The thermostat switches on and off during the normal operational cycle anyway." says Craig. He states the only damage that could occur is to the geyser breaker switch, as it is designed to trip only when there is a problem with the geyser and not designed to be frequently switched on and off.

Switching a geyser on and off will cause it to crack

This is incorrect. Craig says, "The geyser switches on and off during normal operation and is designed to withstand the temperature and pressure created as the water heats up."

Fitting a geyser blanket

According to Craig, a geyser blanket assists with reducing heat loss, keeping the water hotter for longer, which in turn results in less electricity being used, but on its own the average saving achieved with a geyser blanket alone is only about 8%, whereas controlling the operational times of the geyser using a timer would add between 15% and 18% savings over and above the blanket.

Fit a geyser timer

"As a company that has installed more than 1 000 geyser timers, it's a fact that switching the geyser off during peak demand, and operating based on the water usage patterns of the household, makes a significant difference in both cost and demand to both the consumer and the grid." Craig states.

Adapted from article on



back to top