Gas guide
Gas geyser vs electric vs solar geyser
A gas geyser heats water instantly as it flows, an electric geyser heats and stores a tank with an element, and a solar geyser heats a tank from roof collectors with an electric backup. Gas works through load-shedding and has no tank to keep hot; solar has the lowest running cost in sun but costs most to install; electric is simplest but depends on the grid.
Side by side
| Gas geyser | Electric geyser | Solar geyser | |
|---|---|---|---|
| How it heats | Burner heats water as it flows | Element heats a storage tank | Roof collectors heat a tank; element as backup |
| Hot water during load-shedding | Yes (battery igniter) | Only what's left in the tank | Yes in sun; backup needs power |
| Standing heat loss | None — no tank | Yes, tank loses heat all day | Yes, tank |
| Runs out of hot water? | No, while gas lasts | Yes, when the tank is used | Yes, when the tank is used |
| Energy source | LPG cylinders | Mains electricity | Sun + mains backup |
| Certificate needed | Gas COC | Electrical COC | Plumbing/electrical work |
Is gas cheaper than electricity?
No, not always — it depends on your electricity tariff and what you pay for LPG, so compare them in the same unit. One kilogram of LPG holds roughly 46 MJ of energy, about 12.8 kWh. Divide your LPG price per kg by 12.8 to get a price per kWh and set it next to your electricity tariff. A gas geyser also avoids the standing losses of a tank, which an electric geyser pays for every day.
When gas is the right choice
- You want hot water through load-shedding.
- You run out of hot water with the current tank.
- There's an outside wall near the bathrooms for the unit and the cylinders.
Then gas geyser installation is the next step.
When electric or solar suits better
A flat with no outside wall for a flue or cylinders, a body corporate that won't allow cylinders, or a roof with good sun and space for collectors. Many homes keep the electric geyser as a backup when they add gas.
Keeping both
A common set-up: the gas geyser feeds the house and the electric geyser stays connected but switched off, as a backup. The gas side still needs its certificate of compliance.
Get it installed or certified
- Gas geyser installationSized, mounted, piped, certified
- Gas stove installationStove, hob or oven, tested
- Gas certificate of complianceInspection, test, COC
- Get a priceCall 083 498 1693 or use the form
More gas guides
- How a gas geyser works
- Gas vs electric stove
- Gas installation regulations
- SAQCC Gas explained
- Gas cylinder sizes
- Checking for a gas leak
Part of Gas Wizards — gas installers in Johannesburg and the West Rand.
Quick answers
Is a gas geyser better than a solar geyser?
No single answer: gas gives unlimited hot water on demand and works in any weather; solar has lower running costs in sun but needs roof space and a backup.
Can I switch from an electric to a gas geyser?
Yes. The gas unit goes on an outside wall and the hot line is re-routed from it; the electric geyser can stay as a backup.
Does a gas geyser work when it's cloudy or cold?
Yes. A gas geyser doesn't depend on the weather; it heats whenever water flows.