Have looked for a similar problem on this site but cannot find, so apologies if dealt with elsewhere!
Moved into new house - built 1960s. CH system (combi boiler only year and a half old) has big old rads and big steel pipes. 2 extensions were built last year by previous owner and these 2 rooms have new slimmer rads and thin copper pipes.
Problem I have is that these 2 new rads do not get hot. Plumber I know tried to balance the rads but no joy. He said that cos the old pipes were bigger the water was tempted to flow to these first so the new pipes would struggle. I do note that its not only the rad that stays cold but also the upright copper pipes.
He also suggested system needs flushing through as water in one of the new rads was black (which for some reason he couldnt do).
Does this sound plausible?? Is there actually another fault here? Or do I resign myself to a complete overhaul of the CH system?
Moved into new house - built 1960s. CH system (combi boiler only year and a half old) has big old rads and big steel pipes. 2 extensions were built last year by previous owner and these 2 rooms have new slimmer rads and thin copper pipes.
Problem I have is that these 2 new rads do not get hot. Plumber I know tried to balance the rads but no joy. He said that cos the old pipes were bigger the water was tempted to flow to these first so the new pipes would struggle. I do note that its not only the rad that stays cold but also the upright copper pipes.
He also suggested system needs flushing through as water in one of the new rads was black (which for some reason he couldnt do).
Does this sound plausible?? Is there actually another fault here? Or do I resign myself to a complete overhaul of the CH system?