Is a Gas Geyser Cheaper Than an Electric Geyser?
It depends on how many people live in the house, how you use hot water, and what you are currently paying for electricity. A gas geyser heats water only while a tap is running; an electric geyser keeps 150 to 200 litres hot around the clock whether you use it or not. That difference is where the saving comes from — or does not.
How does an electric geyser use electricity?
An element inside the tank heats the whole cylinder of water and then keeps it at temperature all day and all night. Every time you shower, the element switches on again to bring the tank back up. Even on a day nobody is home, it is still topping up.
That constant topping up is what people call standby loss. The tank is insulated, but it still sheds heat into a roof space or an outside wall, and the element quietly replaces it. In most South African homes the geyser is the single biggest item on the bill, which is exactly why so many households in George start looking at gas the day the tariff goes up again.
The other thing homeowners underestimate is recovery time. Once a family of four has drained a 150 litre tank, the last person is showering cold and the element then runs for a long stretch to catch up. You pay twice: once in discomfort, once on the meter.
How does a gas geyser use gas?
Nothing happens until you open a hot tap. The unit senses flow, ignites, and heats the water on its way through to the tap. Close the tap and it shuts down — there is no tank sitting there losing heat.
How much gas that uses depends on four things: how fast the water is flowing, how cold the water is coming in, how hot you have set the unit, and how many minutes the tap is open. A quick hand wash costs almost nothing. A twenty-minute winter shower costs real gas.
Because there is no tank, you also never run out in the way an electric geyser runs out. The hot water keeps coming for as long as there is gas in the cylinder, which is why bigger families notice the change first. If you are weighing up a switch, our gas geyser installations page runs through what a full install involves.
What actually drives the monthly cost?
Not the brand on the front. The monthly figure is driven by how many people are drawing hot water, how long they draw it for, how cold the incoming water is, and where you set the temperature.
- Number of people. Each additional person is another set of showers, dishes and washing-up. This is the single biggest driver on either fuel.
- Shower length. Ten minutes instead of twenty halves the gas burnt for that shower. With gas you feel this directly, because you only pay for the minutes you run.
- Inlet water temperature. George winters bring the mains temperature down, so the burner has to lift the water further to reach the same shower temperature. Your gas will always last longer in February than in July.
- Set point. Running a unit at a scalding setting and then mixing cold back in at the tap wastes gas. Set it to the temperature you actually shower at.
- Pipe runs and losses. A long, uninsulated run from the geyser to the bathroom means litres of already-heated water sitting in the pipe going cold between uses.
Rand figures change every time the tariff or the gas price moves, so we do not publish them. Phone 071 551 2108 and describe your household and we will talk through what is realistic for your house rather than an average one.
When does switching to gas pay off?
Usually at one of four moments: the household has grown, the electricity bill has become the thing you argue about, load shedding has worn you down, or the electric geyser has burst and you need a decision today.
Bigger households benefit most, because the more hot water you draw, the more the on-demand model works in your favour. Small households with modest use sometimes save less than they expect on running cost, but still choose gas for the endless hot water and the fact that it works when the power does not.
The burst geyser moment is the practical one. You are replacing something anyway, the ceiling is already wet, and the price gap between a new electric tank and a gas unit is smaller than people assume once you account for the install you are paying for either way. Our geyser replacement page explains how the electric-to-gas conversion works and what changes in the plumbing.
Which gas geyser fits which home?
Sizing is about demand, not price. As a rough ladder: a flat or granny flat wants a Cadac, a standard family home wants a Dewhot, and a house running multiple bathrooms wants a Paloma or Rinnai.
- Cadac 16L Ecoflow — from around R12,200 installed. Battery-powered, low-flow ignition, sensible for flats, granny flats and rentals. See also gas geysers for flats and granny flats.
- Dewhot 16L Constant Temperature — from around R15,000 supplied and installed. Battery-powered, so it rides out load shedding, but it must be under a weather cover on the Garden Route.
- Rinnai 20L — from around R21,500 installed. Needs a weatherproof plug point, handles mixer taps well, comfortable with whole-house demand.
- Paloma 20L — from around R22,000 installed. Constant temperature, mixer-friendly, no weather cover needed, and one of the two premium units we fit for solar-inline setups.
Correct sizing also depends on your plumbing layout and how many taps run at once, which is why our team measures rather than guesses. The buying guide compares all five models side by side.
Gas vs Electric — Common Questions
There is no honest one-size answer, because a cylinder does not empty by the month — it empties by the litre of hot water you draw. Four people taking long showers every day will go through gas far quicker than a couple who shower for five minutes each. Cold inlet water in a George winter also means the burner works harder for the same shower. The way to plan is to fit a second cylinder on a changeover valve so you are never caught with no hot water, and to phone 071 551 2108 when you want a refill.
Want a straight answer for your house?
Tell us how many people live there, how many bathrooms you run and what you are paying now. You will get an honest view on whether gas is worth it for you, and a quote if it is.