Hi please help!! Since having my central heating put in 12 months since I have had a constant whooshing thought the pipes. It sounds like a kettle boiling. The plumber has been back and put some stuff in the pipes to quieten it down and then came back again and took the thermostat off the the radiator and capped it. This has stopped the noise starting for about 2 hours instead of the usual 1/2 hour but it is still hard to live with. Anybody any ideas, it is driving me around the bend.