RCD or breaker: not the same fault
The RCD (with a test button, 300 mA at the head or 30 mA for bathroom and washing machine) protects people by detecting leakage to earth. The circuit breaker protects the cable and trips on overload or short circuit.
Knowing which one moved immediately narrows the diagnosis.
The five-minute isolation method
It works in nearly every Brussels home.
- Switch off all the circuit breakers.
- Reset the RCD. If it holds, the fault is downstream.
- Switch breakers back on one at a time: the one that trips the RCD identifies the circuit.
- On that circuit, unplug every appliance, then reconnect them one by one.
- If the RCD trips even with all breakers off, the fault is in the panel itself: call an electrician.
The most common Brussels causes
Damp cellars and crawl spaces, ageing water heaters with a leaking element, washing machines at end of life, garden sockets after rain, and above all older installations with no dedicated 30 mA RCD for the bathroom.
In houses split into flats — common in Schaerbeek, Saint-Gilles or Molenbeek — circuits shared between units cause trips that look inexplicable from one flat.
When it is no longer your installation
If the neighbours are also out, if the meter or connection box is hot, or if you smell burning at the meter, touch nothing: call Sibelga on 0800 19 400, free and available 24/7.