OK So he returned to the job.
He agreed there should be some lagging on the pipes and there isn't for nearly 10m through the rafters.
He explained that he used 5m of Heating Pipe which was also had connected the radiator in the bathroom on the same loop into the bathroom upstairs.
This means that all the hot water for the bathroom upstarirs was circulating through the radiator (actually not all as it was in a loop on the same pipework)
He explained that if he removed the radiator this should solve the problem. He removed the radiator and capped off both ends.
Then we started the system up again and alot of brown water came out the hot pipe... But what stunned me, was that brown water came out the cold pipe...?!?? I'm so confused!
I have told him that I want total replacement of the pipework, and that I won't settle until he has dfelivered what I originally quote for.
He tells me the least disturbing way to do this is to run plastic pipe through the loft and drop down into the two bathrooms.
The Floor now has new carpet on it, and the floor to ceiling is only about 4inches deep (wooden joists hodolung up the floorboards) So its difficult to cut in new pipework, which is why they used the old pipework.
he says this is perfectly normal, and happens on alot of construction sites he works on....