Heat Exchanger Replacement Kit for Ultra 155

The Weil-McLain 383-500-775 Replacement Heat Exchanger Kit restores peak efficiency and performance to Weil-McLain Ultra 155 high-efficiency heating systems.

The Weil-McLain 383-500-775 Heat Exchanger Kit is an OEM replacement assembly specifically designed for the Weil-McLain Ultra 155 Series boilers. Constructed with precision-engineered aluminum and stainless steel components, this factory-approved kit ensures optimal heat transfer, energy efficiency, and long-term reliability. It maintains the boiler’s original performance specifications while meeting Weil-McLain’s strict safety and quality standards. Ideal for service professionals and facility maintenance teams, this replacement kit supports proper operation and efficiency in hydronic heating systems.

• Model number 383-500-775 identifies the Weil-McLain OEM Replacement Heat Exchanger Kit designed for the Ultra 155 boiler model.
• Provides a direct replacement for the original factory-installed heat exchanger assembly.
• Restores optimal heating efficiency, performance, and reliability in Weil-McLain Ultra Series systems.

Technical Data & Performance

• Product Type: Replacement Heat Exchanger Kit.
• Brand: Weil-McLain.
• Compatibility: Designed exclusively for Weil-McLain Ultra 155 high-efficiency gas boilers.
• Material Construction: Aluminum alloy heat exchanger core with corrosion-resistant internal coating.
• Application: Hydronic heating systems including baseboard, radiant, and in-floor heating systems.
• Function: Transfers heat from combustion gases to circulating water, ensuring efficient boiler performance.
• Heat Output: Compatible with Ultra 155 models rated up to 155,000 BTU/h input.
• Design Features:
  • Sealed combustion design compatible with condensing boiler operation.
  • Precision-molded water passages for even heat transfer and minimal fouling.
  • High-efficiency condensing surfaces to recover latent heat from exhaust gases.
• Maximum Operating Pressure: 50 psi (345 kPa).
• Maximum Operating Temperature: 210°F (99°C).
• Corrosion Resistance: Engineered to withstand condensate acidity and extended service cycles.
• Efficiency: Maintains Ultra Series’ AFUE rating of up to 94% when properly installed.
• Flow Path: Hydronic water-to-gas interface with counterflow design for maximum heat recovery.
• Included Components:
  • Heat exchanger assembly.
  • Gaskets and O-rings for watertight sealing.
  • Mounting hardware and installation instructions.
• Installation Type: Direct replacement – no modification required when installed on Weil-McLain Ultra 155 units.
• Maintenance: Periodic inspection and cleaning recommended per manufacturer’s service schedule.
• Compliance: Manufactured and tested to meet Weil-McLain quality and safety standards.
• Application Environment: Suitable for residential and light commercial hydronic boiler systems.
• Packaging: Supplied as a complete replacement kit in factory-sealed packaging.
• Replacement Interval: As needed, based on service life, corrosion level, or efficiency decline.
• Dimensions: Sized specifically for Ultra 155 boiler chassis with factory mounting alignment.
• Installation Requirements: Installation must be performed by a qualified HVAC or plumbing professional.
• Warranty: Covered under Weil-McLain’s Limited Warranty when installed per manufacturer’s guidelines.

Applications & Benefits

• Restores factory-rated efficiency and thermal performance to Weil-McLain Ultra 155 systems.
• OEM-certified replacement part ensures compatibility, safety, and warranty protection.
• Corrosion-resistant aluminum construction provides long-term reliability and heat transfer stability.
• Reduces fuel consumption and maintenance costs by maintaining efficient condensing operation.
• Ideal for residential, multifamily, and light commercial hydronic heating applications.