0010002725 Vaillant Ecotec Plus 438 38kw Open Vent Boiler
Open vent systems are normally connected to two tanks in the loft. A small ‘feed and expansion tank’ supplies water to the boiler and the radiators. A larger domestic cold water storage tank provides the cold water feed to an open vent hot water cylinder.
Vaillant open vent boilers:– ecoTEC plus 415, 418, 428 & 438