Radiator nightmare

Hi I woke one morning to a waterfall coming through my living room ceiling turned off combi and water mains called plumber turned out one of the two manifolds that my heating system runs off had burst the original was a 22mm peglar yorkshire with 8 10mm pipes feeding off it 6 used two capped off he replaced it with to black four bore manifolds and now no heat to radiators that come from there he's tried bleeding draining the system etc but can only get heat to pipes when he's bleeding for a long time but never gets to radiators and as soon as he stops bleeding pipes are back cold in minutes anyone have a clue I have my suspicion it's the way he's piped it up

 

Hi I woke one morning to a waterfall coming through my living room ceiling,turned off combi and water mains,called plumber.turned out one of the two manifolds that my heating system runs off had burst,the original was a 22mm peglar yorkshire,with 8 10mm pipes feeding off it,6 are used with two capped off. he replaced it with to black four bore plastic manifolds, now there is no heat to 5 out of seven radiators. He has tried draining the system and tried other things but can only get heat to the pipes under the radiators when he has been bleeding the radiators for a long time,but it never gets to the radiators and as soon as he stops bleeding pipes are back cold in minutes anyone have a clue,I have my suspicion it's the way he's piped it up he has the 22 mm pipe joined up with a piece before the manifolds he has fitted not flowing through them, I rang him back out, he has now suggested changing all the valves on the radiators and putting a chemical through the system,and replacing the other manifold at nearly a thousand quid cost so I have taken off all the rads taken them outside flushed them through until they where clear and changed the valves myself bled the system and now have 4 out of 7 rads working, the 4 that are working are two downstairs bedrooms,utility room downstairs and bathroom upstairs,these all run off the other manifold he hasn't touched, but still can't get heat to the kitchen living room and upstairs bedroom that run off the one he replaced.

 

It's a combi boiler with pressure at 1.5