Gurgling noises in a rad sounds suspiciously like air in the system. Make sure that you bleed the radiator that's highest in the house.
I'd agree that this sounds like a job for a plumber. Especially if the boiler was only replaced 5 months back. You should still have a warranty in place to cover the appliance and fitting.
I'd agree that this sounds like a job for a plumber. Especially if the boiler was only replaced 5 months back. You should still have a warranty in place to cover the appliance and fitting.