ACV Sight glass assy 53418162

The ACV sight glass assembly (SKU 53418162, also listed as 129.748.001) is a boiler housing part designed for visual inspection of the burner flame. It consists of a heat-resistant glass disc, a metal retaining ring or frame, and a sealing gasket. This assembly is compatible with ACV Prestige Solo MK2, HeatMaster 45 TC, and Smart E 130 models. It ensures safe combustion monitoring by providing a transparent window while preventing gas leakage through the gasket.

When selecting a replacement sight glass assembly of this type, confirm the glass diameter, overall thickness, and sealing method (flat gasket or o-ring) against the existing holder. The mounting pattern and clear opening size vary between boiler models and cannot be inferred from part numbers alone. The assembly is typically secured with screws or a bayonet ring; note the orientation of any markings during removal. Ensure the glass rating matches the maximum operating pressure for pressurised systems.

Sight glass assemblies of this kind fail when the glass cracks, becomes heavily sooted, or turns opaque, or when the seal deteriorates. A deteriorated seal can lead to flue gas leakage or water loss. Check for visible damage to the glass and signs of leakage around the gasket. Replace the assembly if the glass is no longer clear or the seal does not hold.