Hello,

My old (oil fired) boiler had a 4mm^2 (ish) earth wire that ran from
the copper oil line back to the CU.

When the (non-oftec) plumber recently installed the new boiler, this
was not reconnected. I am having an oftec plumber coming to sign
everything off. Should I connect the earth before he comes and for my
own safety?

The boiler is earthed but only through the 6A flex.

In my last house the (gas) boiler had all the pipes cross bonded
immediately beneath it. None of the pipes going to or from this boiler
are. I don't think the CH pipes are earthed anywhere. Should they be?

Thanks,
Stephen.