Weil-mclain 311-103-851 Left Hand End Section

Product Description

The WEIL-MCLAIN 311-103-851 is a left hand end section designed as a structural and thermal component of cast-iron sectional boilers. End sections form the outer boundary of the boiler block, containing the waterways and combustion passages that run through the assembly. This section is factory-matched to maintain proper block alignment, flue gas flow, and water-side integrity. Installation is performed by licensed heating contractors or plumbers working on hot water or steam heating systems during new assembly or boiler block repair.

This left hand end section is used with WEIL-MCLAIN CG and CGi series cast-iron sectional boilers. These are residential and light commercial gas-fired boilers commonly found in hydronic heating systems. The section is used when building or rebuilding the boiler block, and must be correctly oriented and nippled to adjacent intermediate sections to form a complete, pressure-tight assembly.

Key Features

• Left hand orientation for correct block assembly positioning
• Designed for use with CG and CGi series WEIL-MCLAIN boilers
• Cast-iron sectional construction for durable, long-service hydronic heating use
• OEM-matched geometry ensures proper nipple alignment and flue passage continuity

Compatibility

Compatible with WEIL-MCLAIN CG and CGi series cast-iron sectional boilers.

Installation Notes

Installation of cast-iron boiler sections should be performed by a licensed plumber or heating contractor familiar with sectional boiler assembly. Shut down and depressurize the boiler system completely before disassembling or adding any block sections. Push nipples, nipple tools, and draw rods are typically required to join and seat sections properly. All work on gas-fired heating equipment must comply with local codes, NFPA 54, and the manufacturer's installation instructions.