nick

Hi, We have had a worcester boiler installed along with new central heating. We have 8 radiators downstairs and 9 upstairs. We find that 1 radiator downstairs does not heat up and 2 upstairs. They have come up occasionally but not consistently. This week it has consistently not come on. The builder has tried removing air, changed thermostats, balancing, and turned up the heat setting on the boiler. None of this has fixed the issue. Can anyone suggest what we should do next. Many Thanks Nick