What breaker for a geyser

Hi all
A quick one, I’ll have to upgrade some electrical stuff in a flat which was wired years ago, so might as well get things closer to spec to eventually get a CoC as well.

These days it’s a requirement to have a breaker within arms reach of a geyser, I read somewhere if you put a double pole breaker at the geyser then you can put a single pole in the DB or vice versa, is this true?
I want to put a CBI Astute in the DB for the geyser.

Then another one, yes I know it’s a how long is a piece of string question. I’ll be replacing the DB with a new bigger surface mount DIN rail over the old DB. How much empty space will you leave for future expantion?

So far if I count all current breakers plus the CBI Astute’s for the geyser and 2 aircons I want to add, oh and a ET112 meter, then I need a 20 way so far.

SANS 10142 rules regarding geysers:

  1. A geyser is a fixed appliance, so you require a disconnecting device within 1.5m from the appliance (
  2. This disconnecting device must break both live and neutral ( A double pole switch in a 4x4 or 2x4 box next to the geyser is commonly used. This is normally fed from a single pole breaker in the DB board. (A double pole breaker is also fine, but not required.)
  3. The breaker in the DB must be of an appropriate rating in order to protect the cable.
  4. You can have multiple geysers on the same breaker, but if you have a geyser on a breaker you cannot have any other type of appliance on it as well (
  5. Geysers must be protected by an earth leakage device (

Thank you sir.

I somehow thought this was not allowed. Is there any other conditions on this?

These are the only two restrictions specific to geysers under the “fixed appliances” section:


I suppose the only restriction would be that the wiring has to be able to carry the peak load when both appliances are active simultaneously, but as long as the wire is sized for it and you have a breaker to protect that wiring, you can have more than one.

I seem to recall, from years ago, that people would sometimes run an air conditioner from the same breaker as the geyser, because there may be enough room on the breaker, and that means they don’t have to fit a new breaker in a (probably full) DB. While it is a neat little workaround, it is of course illegal :slight_smile: