The We recommend at least a 16L fan force driven gas geyser and the bare minimum you would need is a 12L per minute gas geyser for a bathroom. The average shower only consumes +/- 8 litres per minute but you should size your gas geyser with a little bit of buffer in case of very cold days and/or very cold incoming water temperatures.
First. We recommend getting a 16 litre because you could maybe run one tap while someone is in the shower. Running another tap while someone is in the shower is considered taboo in most social circles but it’s bound to happen at some point in time so its wise to size the unit to accommodate that sort of thing.
Second. We recommend a fan forced gas geyser because most major brands have an automatic water flow restrictor so the unit can maintain the target water temperature. Additionally, fan force gas geysers are a lot more efficient as they only heat the water to your set temperature and no more, so you would not add any cold water to your water in the shower.
If you can’t afford a fan forced gas geyser from a major brand then there are cheaper fan forced geysers on the market however they do not feature automatic flow restrictors and may not last as long as the major brand gas geysers.
1. Bosch Optiflow
We recommend the Bosch Optiflow range as they offer good value and come with a controller and have a good back up by Bosch.
Rinnai are known worldwide for offering quality gas appliances and their gas geysers are no exception. There gas geysers do not come with controllers but they are avabalbe and offer extra fuctionalites like a bath fill function.
The Paloma range have efficiencies that are on par with both Bosch and Rinnai. Paloma gas geysers do not come with controllers however there controllers are affordable and the units themselves are normally cheaper than Bosch and Rinnai.