Description
Weil McLain 383-700-148 Expansion Tank for WM97+ 70/110
The Weil McLain 383-700-148 is a genuine OEM replacement expansion tank engineered specifically for use with the Weil McLain WM97+ condensing gas boiler in the 70 MBH and 110 MBH configurations. Designed as a direct-fit component, this expansion tank integrates seamlessly with the WM97+ hydronic heating system to maintain proper system pressure, protect the boiler and associated piping from pressure fluctuations, and extend the service life of the overall heating system.
Why Use a Genuine OEM Expansion Tank?
Using the correct OEM-specified expansion tank is critical in high-efficiency condensing boiler applications. The WM97+ operates as a sealed hydronic system, and the expansion tank must be properly sized and rated to accommodate thermal expansion of the system water. A correctly functioning expansion tank prevents nuisance pressure relief valve discharges, protects system components from overpressure, and helps maintain consistent, efficient boiler operation.
Key Features
- Genuine Weil McLain OEM replacement part — SKU 383-700-148
- Designed for direct compatibility with WM97+ 70 and 110 MBH boiler models
- Maintains proper system pressure in sealed hydronic heating systems
- Helps prevent pressure relief valve discharge due to thermal expansion
- Protects boiler components and piping from overpressure conditions
- Supports long-term reliability and efficiency of the WM97+ condensing boiler
Compatible Equipment
- Weil McLain WM97+ 70 MBH Condensing Gas Boiler
- Weil McLain WM97+ 110 MBH Condensing Gas Boiler
About the Weil McLain WM97+ Series
The WM97+ is a wall-hung, high-efficiency condensing gas boiler delivering up to 97% AFUE. It is designed for residential and light commercial hydronic heating applications and requires properly sized system components — including the expansion tank — to operate at peak performance. Always use genuine Weil McLain replacement parts to ensure warranty compliance and optimal system operation.
