Your geyser doesn't need to heat water every minute, which adds to your electricity bill. Even when nobody opens a tap, heat gradually escapes from the tank.

A timer can reduce some of that heat loss by controlling when water is heated. But shorter showers and repaired hot-water leaks tackle another expense: the energy needed to heat the cold water replacing what you use.

Eskom identifies using less hot water as one of the most effective ways to reduce water-heating energy consumption. 

Off or On: What Actually Saves?

A functioning thermostat switches the element off when the water reaches its set temperature. Leaving the geyser switched on therefore does not mean the element runs continuously. It reheats water as the temperature drops. 

Switching off allows the water to cool gradually. As it cools, it loses heat more slowly, so reheating later does not automatically cancel the saving.

Stellenbosch University research, using a model checked against actual geyser usage data, found that scheduling could reduce water-heating electricity consumption. Results varied with household routines. 

A suitable schedule can save electricity, but there is no universal “two hours a day” rule. Tank size, element capacity, insulation and hot-water demand affect how much heating time is needed.

Start With These Practical Changes

• Shorten showers: A short shower generally uses less hot water than filling a bath. Long showers can undo that advantage.
• Repair dripping hot taps: They waste both water and the electricity used to heat it.
• Consider an efficient showerhead: A suitable low-flow model reduces hot-water use per minute.
• Check the temperature: Eskom recommends 60°C. Ask a qualified person to check the setting rather than opening electrical covers yourself.
• Review insulation: Ask an installer whether the tank and nearby hot-water pipes need suitable insulation to reduce heat loss. 

Make a Timer Work for Your Household

If your household mainly needs hot water at predictable times, a timer can schedule heating around that routine. Depending on its features, a smart controller may also monitor temperature or electricity consumption.

Before buying or changing settings:

• List when hot water is needed, including different morning and evening routines.
• Allow enough reheating time for everyone’s needs.
• Use a qualified installer to select and configure suitable equipment.
• Ask what the savings claim covers: Reduced geyser consumption is not the same percentage reduction in your entire electricity bill.

Moving heating to another time only gives a direct cheaper-rate benefit if your electricity tariff charges different prices at different times.

Keep Stored Water Safely Heated

Do not lower the thermostat to a lukewarm setting or configure a schedule that leaves stored water inadequately heated for prolonged periods.

NICD identifies warm, stagnant water as favourable for Legionella, bacteria that can cause serious illness. Ask your installer to account for temperature safety when configuring the system. 

Check Whether You Are Saving

Compare electricity consumption in kilowatt-hours, rather than only comparing rand spent. Price changes and other household appliances can affect the bill.

Where available, separate geyser monitoring makes the comparison clearer. Keep household occupancy and hot-water use reasonably similar when assessing a change.

The Bottom Line

Switching a geyser off can save electricity when the schedule suits the household and maintains safe heating. Start by reducing unnecessary hot-water use and fixing leaks, then use controls and insulation to support those savings.