Immersion trips RCD but not straight away

[Burt Stormberger]

Hi everyone

My immersion heater is tripping the RCD, but it doesn't trip straight away, it strips about 30-60 seconds after coming on and when it is on you can hear it making the normal noise associated with a working immersion.

The heating engineer says that he thinks the immersion is fine as its not tripping straight away and sounds OK and has replaced the stat which hasn't helped. He's suggested an electrician look at the rest of the circuit / MCB / RCD.

The electrican doesn't think it can be anything other than the immersion, but hasn't seen one before that doesn't trip the RCD straight away.

Who is right, what do I do? I'm stuck in the middle with no hot water.

Thanks!!
Burt

 

[HERTS P&D]

Just fit a new complete immersion.

Andy

 

[pete50]

Yep as above. As it gets hot the internal insulation breaks down and the element shorts and trips the RCD. Just replace the immersion element.

 

[ianmcd]

That is some Electrician that you have , and I am a gas engineer