BIASI ADVANCE PLUS 16S 25S 30S 25C 30C 35C BOILER GAS VALVE BI1313103
ADVANCE 25S - 41-583-33. ADVANCE PLUS 25S ERP - 41-583-28. ADVANCE PLUS 16S ERP - 41-583-27. ADVANCE 35C - 47-583-45. It's important to note that installation of the gas valve in the boiler should be done by a Gas Safe engineer.