Is it acceptable run main protective bonding conductor to central heating pipework and then link gas and water pipes under boiler?

In theory yes, but you need to take precautions against any part of the metallic pipework being removed - e.g. by a plumber affecting a repair with a plastic push-fit fitting (543.2.6 (iii)) - which I suspect is going to be tricky in an uncontrolled environment like a domestic without something drastic like putting labels every12" along the pipe (which presumably defeats the idea).

Do the water and gas come out of the ground in metallic pipes? Most are plastic these days, meaning bonding usually isn't needed even if the internal pipework is copper.

   - Andy.

Yes Andy,take your point about later alterations to the pipework.The house is about 40 years old,but will

check out the incoming supplies.

                                                 Thanks,

                                                           Hz

Yes Andy,take your point about later alterations to the pipework.The house is about 40 years old,but will

check out the incoming supplies.

                                                 Thanks,

                                                           Hz

I wouldn't be at all surprised if the utilities arrive in plastic pipes in a 40 y.o. house.

I find it slightly difficult to believe that main bonding would have been entirely omitted in error, but perhaps it was.

There was a transition from supplementary bonding to RCD for additional protection around then, so can you tell us a bit more about the CU please?