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How to keep yourself in and out of hot water

Geysers account for up to 50% of a typical electricity bill.
The Blue Lagoon geothermal spa in Iceland is kept nicely warm by the forces of nature, but we need geysers – and electricity. Photographer: Arnaldur Halldorsson/Bloomberg

The simplest way to reduce your geyser cost is to switch it on and off each day, but the savings benefit will depend on how long you leave it on before switching it off.

“Typically, a geyser would need to be off for 20 hours or on for only four hours to see a small saving,” says New Southern Energy MD Deepak John. “The longer you can keep the geyser off, the greater the savings.”

According to Eskom, a three kilowatt (KW) 150-litre geyser takes less than three hours to heat water from 20ºC to 65ºC. Before you start protesting, it’s worth noting that if you switch your geyser off, the temperature of the water typically only drops by 10ºC over a 24-hour period.

Separating fact from fiction

Here’s what you need to know when it comes to how best to use your geyser.

Myth: Switching your geyser on and off regularly will damage the thermostat. Fact: The geyser thermostat is actually designed to switch on and off, so it will not be damaged.

Myth: Switching your geyser on and off regularly will cause the geyser to crack. Fact: The thermal range of a geyser, when it remains switched on, is greater than the slow cooling rate of a geyser that has been switched off, so switching it on and off will not cause it to crack.

Myth: You should use an automatic timer rather than switching the geyser on and off manually, as this is less likely to damage the geyser. Fact: The major difference is that the latter requires manual operation and you have to remember to turn the switch on and off. John says a timer simply provides the benefit of always switching the geyser on and off as it is programmed to do so, but this comes with a fee. “A standard timer would cost around R 700 for the component and another R 700 for installation,” he says, adding that using an automatic timer reduces the risk of damage to the surge arrestor and other electrical components.

Myth: You should keep your geyser temperature high so that it takes less time to heat up the water. Fact: Eskom says that a family using 200 litres of water a day and a 150-litre geyser can save as much as 122 kilowatt hours (kWh) of energy a month if they drop the thermostat temperature from 70ºC to 60ºC and keep the geyser off from 6am to 9pm (15 hours) each day. In fact, just dropping the temperature setting from 70ºC to 60ºC and keeping the geyser on for 24 hours will reduce your electricity usage from 360kWh to 342kWh.

Keeping your geyser in tip-top condition

Old Mutual’s short-term insurance arm iWyze notes that geyser claims tend to increase by about 23% in the winter months (May, June and July in South Africa), and offers the following tips for geyser maintenance:

  • Check to ensure that pipes and valves to and from the geyser are not clogged or blocked as this could increase pressure.
  • Check that the thermostat is functioning correctly.
  • Install a geyser blanket to help insulate the geyser. These are available for between R140 to R360 at Builders Warehouse and, according to insulation company Isotherm, can reduce electricity costs by 20% while insulating your pipes (as well as the geyser) can cut electricity costs by a further 10%.
  • Ensure that you have a drip tray underneath the geyser, which can direct water away to an overflow pipe if the geyser does burst.
  • Have the geyser serviced by a qualified plumber every three years. This involves checking the components including the anode, element and thermostat, as well as the whole system for possible leaks. A qualified plumber should also check that your geyser has all the important safety features such as a shut-off valve, vacuum breakers and a temperature and pressure safety valve.



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Make sense, a solar geyser next or gas.

Not really on the topic but my pet hate is the geyser with the 5 year “warranty” that lasts 5 years and 2 months. I have had 3 or 4 of these and the inconvenience and ceiling destruction adds a further irritation.

Ad on, of topic, most car battery’s. It is local and perfected.

Paul- go gas. I replaced boht my geysers with gas when they burst many years ago. No problems and save a lot of electricity. Why they put the geysers in the ceilings is beyond me. Plumber told me the same thing about the geyser warranty. Same with car batteries. lasts 2years and 1 day.

Soweto resident: “Whatz a electricity bill?”

I’ve installed an ITS HEAT PUMP in 2013 & by now has paid for itself (our elec cost is about R300-R400 p.m. for a 2-person household).

Like solar (or gas) a heat pump has the advantage that there’s no worries about faulty thermostat, anode or element within geyser tank (as its disconnected inside drum).

You can enjoy searing hot water from 10-15 minutes. You can time it perfectly before bathing time.

HP has little maintenance…just like an outside Aircon, keep it free from leaves/debris. Some cheaper roof-solar geysers have the propensity to start rusting (staining roof) or leaking over time. (…shoddy installation workmanship also to blame)

Heat Pumps have easily accessible controller boxes, where you can program the timer-settings, water temp range, etc…without climbing onto the ceiling to make temp adjustments.

Heat Pumps are said to be more “softer” on geyser longevity (?)

No worries also if your next-door neighbor’s trees (or high walls/roof line) blocks the sun from your solar array, as the sun moves about during a day. A Heat Pump also works after dark, and during freezing cold days (just takes longer to reach same result)

Gas…yes, it heats up quickly / works great…but, like petrol, gas cylinder has to be refilled at quite a cost.

Only disadvantage of HP is it does not work when Eskom is off / load-shedding, but one can plan around it. Takes a very short time to heat water, esp in summer’s hot ambient air.

For the half-and-hour or so when a Heat Pump is running, it draws the wattage of a typical vacuum cleaner (1,000w) while providing 4,000w heat to the geyser.

“Don’t CREATE heat. Just TRANSFER it!”


I went solar thermal on 300 liter system, backed up by heat pump (also ITS brand) about same time. The solar works really well, pretty much use no energy in summer. The heat pump does use less energy to heat 100 liters by 40 degrees – probably a third as much, but what the buggers forget to tell you is that it also takes three times longer if ambient temperature is around zero! And that is when the hot water is most needed. When we have full house, we run out of hot water in mornings because the heat pump is too slow and everybody showering same time. No issue if we are few people.

If I redid our setup I would go solar thermal backed up by gas. There is an auto system that will heat water leaving geyser to at least 40 degrees (or whatever setting). That way can have 10 guests and all have at minimum a warm-enough shower.

But to article, dumping geyser element makes massive difference on electricity bill.

“….Have the geyser serviced by a qualified plumber every three years. This involves checking the components including the anode, ….”

a Steel geyser needs an anode, the anode’s job is to corrode away instead of the steel components (ie element, thermostat), after that the element / thermostat / screwthreads will rust and presto a leaking / burst geyser.

When will people learn?


The higher buy price is a ONCE-OFF expence.
Then you don’t need a anode.
I build my house in 1984 and installed two copper geysers. They are still working.
My Grandmothers copper geyser lasted more than 30 years (the house was sold in the meantime so I don’t know if it still exists)

BUT steel geysers — previously I lived in a block of flats (40 flats) for about 6 years and in that time about an average of two geysers per flat had to be replaced (including mine).
a Colleugue of mine had to replace his geyser, ditto another colleague, another friend, also next door neighbour, as well as neighbour across the street, and also that one’s next door neighbour…… All were geysers of a well known steel geyser manufacturer, so one would think that there would be a good standard ie quality of product.

In a hardware store I heard a sales man painting himself into a corner about the above when I told the customer to stay away from steel, by saying to a customer “..but you must remember that we live close to the sea..”

I’ve also heard salesmen say “But they don’t manufacture copper geysers any more”.
There’s SolardomeSA in Stellenbosch, there’s Tecron in Epping, cape Town to name but two.

Stay away from steel geysers.
You have been warned!

Ag no man. We are supposed to SUPPORT Eskom by using more power, not less.

End of comments.





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