How Long Does a Geyser Take to Heat Up? (South Africa Guide)
24 May 2026 · Plumbers On Duty
Quick answer
A standard 150-litre electric geyser in South Africa takes between 1.5 and 3 hours to heat from cold to around 60–65°C. A 200L geyser takes 2 to 4 hours, and a 100L geyser takes about 1 to 2 hours.
If yours is taking significantly longer than this, something is wrong. Find a geyser plumber near you.
Heat-up time by geyser size
| Geyser size | Cold-to-hot time | Element |
|---|---|---|
| 100L | 1–2 hours | 2kW or 3kW |
| 150L | 1.5–3 hours | 3kW or 4kW |
| 200L | 2–4 hours | 3kW or 4kW |
| 250L | 3–5 hours | 4kW |
What affects heat-up time
- Element wattage — a 4kW element heats roughly 33% faster than a 3kW element of the same size
- Inlet water temperature — winter water in Joburg or Bloem can be 10°C colder than summer
- Thermostat setting — most geysers are set to 60°C (Eskom recommendation); higher settings take longer
- Scale and sediment — a geyser that has not been serviced in 5+ years can take 50% longer to heat
- Loadshedding — if power cut mid-cycle, the cycle restarts
When slow heating means you need a plumber
Call a plumber if:
- A full 150L geyser takes more than 4 hours to heat
- The water never gets properly hot, only warm
- You hear popping, knocking or rumbling from the geyser (sediment build-up)
- The geyser trips your DB board when it switches on (element earth leak)
- You notice rust-coloured water (anode rod failure — geyser is corroding internally)
All of these are fixable, and catching them early can add years to your geyser life.
How to make your geyser heat faster
- Drop the demand — install low-flow shower heads so you use less hot water per shower
- Insulate the geyser and pipes — a R300 geyser blanket pays for itself in a few months
- Service every 3–5 years — a plumber drains, descales, replaces the anode rod and checks the element
- Consider a heat pump — uses 60% less electricity than an element and heats more consistently
Loadshedding and your geyser
During Stage 4+ loadshedding your geyser may only have 6–10 hours of power per day. A 150L geyser that is fully cold needs about 3 hours of continuous power to heat. If you only get 2-hour power slots, set your geyser to come on first when power returns by turning everything else off at the DB.
Need a plumber?
If your geyser is slow, leaking, or making noise, get it checked before it bursts — a burst geyser causes thousands of rands in ceiling and floor damage.