The core tradeoff
Electric geysers are cheap to install but expensive to run. Gas geysers cost more to install and require an ongoing gas supply, but heat water on demand — you only pay for gas when you actually use hot water. Whether gas is cheaper depends on your usage pattern and gas price.
Running cost comparison (2026)
| 150L electric (standard) | Gas instantaneous (16L/min) | |
|---|---|---|
| Installed cost | R7,000–R11,000 | R8,000–R18,000 |
| Monthly energy cost (family of 4) | R600–R900 | R280–R500 (LPG) |
| Works during load-shedding? | No (element needs power) | Yes (most models use battery ignition) |
| Lifespan | 8–12 years | 10–15 years |
| COC required? | Yes | Yes (plumbing + gas) |
Gas geyser advantages
- Lower monthly running cost — typically R250–R400/month saving
- Instant hot water — no waiting for tank to re-heat
- Works during load-shedding (battery-ignition models)
- No heat loss from standing water in a tank
Gas geyser disadvantages
- Ongoing gas cylinder cost and logistics (LPG at ~R370–R450 per 9kg cylinder)
- Requires outdoor installation or adequate ventilation — cannot be installed in enclosed spaces
- Gas regulations (SANS 10087) add compliance requirements
- High hot water demand (large family, multiple simultaneous showers) may need multiple units or larger capacity
Which is best for South Africa?
- Apartments / small homes: Gas instantaneous — lower running cost, no tank space needed
- Families of 4+ with high demand: Heat pump or solar geyser — bigger saving over time
- Already have solar PV: Keep/install electric geyser + geyser controller — power it from your panels for near-zero running cost
- Load-shedding priority: Gas (works 24/7) or solar thermal (stored heat)
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