|I don't know what
|Photographed in a
shall be nameless) on the Isle of Wight.
Many radiators have an automatic air vent (AAV) fitted directly to them in lieu of the traditional manual air vent.
Did it not occur to the Heating Contractor who installed them, there was something more seriously wrong with the design of the pipework system that allowed air to enter the pipework in such quantities that some radiators became continuously air-locked.
If you know the design fault then email the Webmaster. No prizes will be awarded, but your reply will be answered.