Will fit: VAILLANT ECOTEC PLUS 612 VU BOILER. VAILLANT ECOTEC PLUS 615 VU BOILER. VAILLANT ECOTEC PLUS 618 VU BOILER. VAILLANT ECOTEC PLUS 624 VU BOILER. VAILLANT ECOTEC PLUS 630 VU BOILER. Products will not be covered if misused or not serviced as per maintenance instructions.