JUST RECENTLY HAD AN OVERHEAT PROBLEM WITH MY BOILER WHIH is now fixed but now i hav a leak in the airing cupboard from a cyclindrical obgect about 5 inch high with two pipes from the bottom and one from the top which goes into the loft. anyone no what this is and where to get one. I THINK ITS AN AIR TRAPPING DEVICE. CAN I GET ONE FROM SOMEWHERE