Weil‑McLain 203K BTU Gold S4 Oil-Fired Water Boiler

A high‑capacity five‑section cast‑iron Oil-Fired Water Boiler engineered for strong hydronic output, long service life, and reliable domestic‑hot‑water production. Built on the proven Weil‑McLain Gold platform, the 386701030 arrives as a factory‑packaged unit with burner installed, ensuring proper alignment, consistent ignition, and reduced installation time. This Oil-Fired Water Boiler includes an integrated tankless coil, providing on‑demand domestic hot water without the need for an indirect tank. Designed for natural‑draft chimney venting, it is a straightforward replacement for older atmospheric oil boilers in larger homes.

Key Features
Five‑section cast‑iron heat exchanger delivering high output, thermal stability, and long‑term durability.

203,000 BTU heating capacity suited for larger homes or higher‑demand hydronic systems.

Integrated tankless coil providing continuous domestic hot water directly from the boiler.

Factory‑installed oil burner matched to the boiler’s firing rate for clean, stable combustion.

86% AFUE efficiency offering dependable performance with simple annual maintenance.

Natural‑draft chimney venting ideal for retrofit installations using existing flue systems.

Quiet, low‑vibration operation supported by Weil‑McLain’s combustion chamber and block design.

Service‑friendly layout with accessible burner, controls, and piping connections.

Ideal Applications
Larger homes needing a high‑capacity oil boiler that provides both hydronic heat and on‑demand domestic hot water through a built‑in tankless coil, especially where chimney venting is already in place.

We service and install all types of HVAC heating and cooling equipment throughout Long Island, including (but not limited to):

Nassau County: Oyster Bay, Hempstead, North Hempstead, Glen Cove, Long Beach, Freeport, Valley Stream, Garden City, Great Neck, Mineola, Hicksville, Levittown, Massapequa, Bethpage, Plainview, Syosset, Jericho, Westbury, Rockville Centre, Farmingdale

Suffolk County: Huntington, Babylon, Islip, Smithtown, Brookhaven, Riverhead, Shelter Island, Southold, Southampton, East Hampton, Commack, Deer Park, Lindenhurst, Bay Shore, Brentwood, Central Islip, Hauppauge, Centereach, Selden, Medford, Patchogue, Shirley

Contact us today at (631) 779-3196