Tankless vs. Tank Geyser in Pretoria East
Electric tankless against electric storage: what's actually sold locally, what the circuit and water pressure demand, and why Faerie Glen and Equestria face extra risk.
This guide compares electric tankless and electric storage geysers for Pretoria East homes: same fuel source, different mechanism, and what that means for installation, water pressure, and multiple bathrooms.
Gas geysers are a separate category: every gas geyser sold in South Africa is instantaneous by design. This piece stays entirely on the electric side, tankless against storage.
That's the more useful comparison if gas isn't on the table, or you've already ruled it out. It comes down to what's actually sold locally, what the electrics and water pressure demand, and how each one copes when more than one bathroom needs hot water at once.
Electric tankless vs. electric storage: how each one actually heats water
A standard electric geyser stores a full tank of water, heats it, then keeps that tank topped up at temperature around the clock, whether or not anyone's using hot water at that moment.
An electric tankless unit skips the tank. Cold water flows past a bank of heating elements, and those elements fire the moment flow is detected, heating water in the pipe as it passes through. Nothing sits stored and pre-heated.
That's the same basic principle a gas geyser uses, minus the flame. Our guide comparing gas and electric geysers covers the gas side of instantaneous heating in full; this one stays on the electric side of that mechanism.
Electric tankless in South Africa: small, single-outlet units
Most electric tankless units sold in South Africa are point-of-use units, sized to serve one outlet at a time. That's a different category from the large whole-house systems some overseas guides describe.
Retail listings show the range clearly:
- Ewube units: 5.5 to 6kW
- Ariston Aures units: 9.5kW (around R2,613) or 12kW (around R3,028)
Unit price is only part of the total. Installation adds two further costs on top: the electrical work for a dedicated circuit, and the plumbing labour to fit the unit itself.
A distribution board that already has spare capacity for a new circuit keeps those added costs to labour alone. A board that needs upgrading adds that work to the total as well.
There's also a different sizing question here. Our guide to geyser installation in Pretoria East sizes a storage tank by household size. A tankless unit sizes differently: by flow rate and kW, not by litres at all.
Installation: the electrical circuit and the water pressure both matter
A tankless unit's heating elements draw a lot of power in a short burst, more than a standard plug circuit is built for. Most installations need a dedicated 32 to 40A circuit, and older homes often don't already have that headroom on the distribution board, forcing an upgrade before the unit itself goes in.
Water pressure matters just as much, and it's the part homeowners tend to miss. A tankless unit needs roughly 150 to 300 kPa of inlet pressure just to activate at all. Below that, it either won't fire or will cut in and out.
This is where Pretoria East's own water network becomes relevant. Faerie Glen (Extension 50 and above) and Equestria are named as high-lying, low-pressure-risk suburbs, served last when reservoir levels can't maintain standard distribution pressure.
Tshwane's reservoirs have repeatedly run critically low through 2026, and the City has deliberately reduced network pressure during shortages to manage the strain. Normal household pressure sits at 200 to 400 kPa; anything below 150 kPa counts as restricted.
A household in Faerie Glen or Equestria already sitting near that 150 kPa line during a supply strain is exactly the household where a tankless unit risks not firing reliably, independent of anything electrical.
A tankless unit's footprint is smaller too. No tank means no roof or cupboard space taken up, which is why they suit sectional title units, backyard flats, and space-constrained retrofits particularly well.
A compliant install needs sign-off on both sides of the job. The plumbing itself needs a Certificate of Compliance from a PIRB-registered plumber, same as any geyser installation. The added electrical work, the dedicated circuit and possible distribution-board upgrade, needs its own Electrical Certificate of Compliance under SANS 10142-1:2020, separate legal sign-off from the plumbing side.
Multiple bathrooms and running more than one shower at once
A single shower needs roughly 10 to 12 litres of hot water a minute. Run two showers at the same time and that demand roughly doubles.
A small point-of-use tankless unit, the kind actually sold in South African retail, can't keep up with that on its own. As a general industry sizing benchmark, not confirmed against South African-specific data: a 10kW unit generally covers one to two bathrooms; serving three to four bathrooms with real simultaneous demand needs 27kW or more.
A unit in that range needs a bigger electrical upgrade than the standard single dedicated circuit, a different scale of work than most Pretoria East retrofits are set up for.
A standard electric storage geyser works within a different constraint. Its tank holds a fixed volume of hot water, and that volume runs down as taps stay open, regardless of how many are open at once. Tank size is what determines how many showers it can support back to back.
Lifespan and the running cost that builds up over time
Tankless units are commonly cited at 15 to 20 years. A standard enamel-lined storage geyser runs 8 to 12 years, the same range our guide to geyser lifespan uses for a well-maintained tank.
That's a real longevity advantage for tankless units.
In hard-water municipalities, tankless units typically need annual descaling to keep the heating elements working properly. Flushing and descaling costs add up over the unit's life, adding to the running cost of tankless ownership.
Whether that's a meaningful factor for your specific home depends on local water hardness, which isn't confirmed one way or the other for Pretoria East in this guide. Treat descaling as a real, recurring cost to budget for.
Load-shedding: the buffer difference between storage and tankless
A well-insulated 150 to 200 litre storage geyser holds usable hot water for roughly 4 to 6 hours after the power cuts. That stored heat doesn't disappear the moment load-shedding starts.
A tankless unit has no such buffer. There's no tank to hold residual heat, so the moment the power goes off, hot water output stops immediately, with nothing in reserve.
This is a different comparison from the one covered in our guide comparing gas and electric geysers, which looks at gas's independence from the grid entirely. Here, both options are electric: storage simply has a several-hour head start; tankless has none.
Which one is right for your home?
A single-bathroom home with stable water pressure and a distribution board that already has spare capacity is a reasonable candidate for tankless. It's compact and lasts longer than a standard storage tank.
A multi-bathroom household, or a home in a lower-pressure area like Faerie Glen or Equestria, is usually better served by a standard storage geyser. It handles multiple simultaneous outlets without a major electrical upgrade, and it switches on regardless of inlet pressure.
Weighing a straight electric replacement against a tankless retrofit? Our geyser replacement page has next steps and pricing for the standard route.
Tankless vs Tank Geysers — Common Questions
Can you have a tankless water heater without gas?
Yes, electric tankless units run entirely on electricity, ranging from 5.5kW to 12kW for the point-of-use models sold in South Africa, with no gas connection required. That's a different category from the whole-house tankless systems used in some other markets. There's no gas involved, so SAQCC Gas registration and flue venting don't apply to these units. Installation for an electric tankless unit runs through the electrical and water-pressure requirements covered above.
What size tankless water heater do I need?
A 10kW unit generally covers one to two bathrooms; serving three to four bathrooms with simultaneous demand needs 27kW or more, per general industry sizing guidance. That's a bigger jump than the single dedicated circuit most Pretoria East retrofits install for, since higher-output units need a larger electrical upgrade than that. For a single bathroom, the 5.5 to 12kW units actually sold in South African retail are usually enough.
Is a tankless water heater better than a tank geyser?
It depends on your home: tankless suits a single bathroom with stable water pressure above 150 kPa and spare distribution-board capacity. A standard storage geyser suits multi-bathroom homes and lower-pressure areas better.
Electric tankless water heater price in South Africa
A small electric tankless unit costs roughly R2,600 to R3,000 for the unit alone, covering point-of-use models like the Ariston Aures at 9.5 to 12kW. That price covers the unit only. Installation adds electrical work for a dedicated circuit and plumbing labour to fit it. Get a distribution-board assessment before budgeting: it tells you whether your home already has spare capacity for the new circuit, or needs an upgrade first.
Will low water pressure stop a tankless geyser from working in Pretoria East?
Yes, most tankless units need roughly 150 to 300 kPa of inlet pressure just to activate at all, below which they won't fire or will cut in and out. In Pretoria East specifically, Faerie Glen (Extension 50 and above) and Equestria carry that risk: both sit high-lying and are served last when reservoir levels drop, per Tshwane's ongoing 2026 reservoir strain. Normal household pressure runs 200 to 400 kPa; below 150 kPa counts as restricted.
Tankless geysers South Africa: what's actually sold here?
Electric tankless units sold in South Africa are small, point-of-use models, typically 5.5 to 12kW, built to serve one outlet rather than an entire whole-house system. Retail listings show a range from smaller Ewube units at 5.5 to 6kW up to larger Ariston Aures models at 9.5 to 12kW, priced from roughly R2,600 to R3,000 for the unit alone. That's a very different product from the 27kW-plus whole-house tankless systems some overseas guides describe.