A major problem with central heating is air in the system. It can cause banging, whistling or howling noises as well as an increase in corrosion of the radiators and the boiler. Try fitting a de-aerator to the vent pipe. Choose a de-aerator suitable for connecting to compression fittings if you do not want to use soldered capillary joints. The de-aerator is shaped like a bottle and made of copper. It works automatically by 'beating' the air out of the water system by causing turbulence.
roy, January 2011
