Electric Shower Keeps Tripping Consumer Unit Ask questions and find answers to many subjects relating to electrics and electrical work

[nitro23456]

Hi - I have a Triton electric 8.5kw shower above my bath that was installed before I lived in my house. It all used to work well and seems to have been installed correctly with separate cable runs etc.

However it now trips both the MCB for its circuit on the consumer unit and the RCD on the consumer unit. I have a cord switch in the hallway outside the bathroom upstairs which when I pull the cord it turns the power on and the red light shows on the switch box. But when I then turn the shower on in the bath everyhing trips within two seconds.

It has been suggested to me that it might actually be the cord switch that needs replacing rather than the shower - what do you think?

Also, on a side note, whats the difference between the MCB and RCD and why do I need the cord switch outside the bathroom as well - not sure what this is called.

[ericmark]

The fault is more likely your shower and is quite common when the heating element burns out.
MCB’s protect against the appliance drawing too much current.
RCD protects against current going to earth.
RCBO combines both together in the same unit.
The cord operated switch as called in BS 7671 is to allow isolation in the event of a problem normally is view of anyone who may have to work on the shower. Although with no locking ability not quite sure how it fits in to the regulations. I am sure someone will tell us.