This is the one problem on this site where the advice is to stop.
The likely cause
A heating element breaking down. Elements are resistance wire inside a metal sheath, insulated by packed mineral powder. When the sheath cracks or the insulation absorbs moisture, current leaks to earth — and an RCD or residual-current device trips exactly as designed.
That trip is protecting you from a shock. Resetting it and carrying on removes the protection while the fault remains.
Other possibilities
A failing pump drawing excessive current, which trips an overcurrent breaker rather than an RCD.
Water where it should not be, from a split hose or a leaking boiler seal, bridging live parts to earth.
A fault elsewhere in the house that the coffee machine’s load merely reveals.
How to narrow it
If it trips the instant you switch on, it is likely a short. If it trips when it starts heating, that points to the element. If it trips when the pump runs, the pump or a leak.
What to do
Unplug it. Do not use it. Do not tape the breaker.
Element replacement is a routine repair on serviceable machines and often not economic on sealed ones. Either way it is a job for someone qualified — this is mains voltage next to water.
Last reviewed 8 August 2026