Oil-Fired Boiler and Rear Flue Kit with Coil, 88-110 MBH

Thermo-Dynamics CWL85-110LE – Oil-Fired Boiler with Tankless Coil, Compact Wet-Base Design

The Thermo-Dynamics CWL85-110LE is a low-profile, oil-fired cast iron boiler featuring a 360° wet-leg combustion chamber and integrated domestic hot water coil. Designed for tight mechanical spaces and high-efficiency hydronic heating, this unit is field-rated for multiple firing rates to match heat load requirements without oversizing the system.

Engineering Highlights

• Round Wet-Base Heat Exchanger: Water surrounds the entire combustion zone, improving thermal efficiency and reducing standby losses compared to dry-base boilers.
• Field-Adjustable Firing Rates: Unit is UL-listed for multiple nozzle sizes, allowing firing rates from 0.85 to 1.10 GPH (up to 110,000 BTU/h input) to suit load sizing and improve seasonal efficiency.
• Compact Footprint: Overall height of 29.5" facilitates installation in basements and confined utility rooms.
• Tankless DHW Coil: Standard 5-gallon-per-minute coil draws from a 15-gallon reservoir, eliminating the need for a separate indirect or storage tank in small-to-moderate applications.
• Venting Flexibility: Rear or top venting is field-selectable by repositioning the flue collector box, simplifying flue alignment on retrofit jobs.

Technical Specifications

• Model: CWL85-110LE
• Input: 110,000 BTU/hr (1.10 GPH max)
• Net I=B=R Output: 88,000 BTU/hr (Water)
• Combustion Chamber: Circular, fully water-backed design
• Water Content: 15 gallons
• DHW Coil: 5 GPM, copper tankless coil
• Draft: Natural draft; chimney-vented
• Venting Options: Rear or vertical venting (field configurable)
• Construction: Cast iron sections, ASME-rated and hydrostatically tested

Installation Notes

The CWL85-110LE is designed for residential hot water heating systems requiring integrated DHW production and adaptable installation in confined areas. All units must be installed in accordance with local code and manufacturer instructions. Flue piping, barometric draft control, circulator sizing, and combustion setup should be completed by a qualified technician. Field-adjustable firing rate allows the installer to dial in the required input during commissioning.

Contractor Considerations

• ASME H-stamped heat exchanger and factory hydrotest ensure pressure vessel integrity
• Suitable for baseboard, fin-tube, and low-mass panel radiator applications
• Direct replacement in retrofit jobs due to flexible flue orientation and compact size
• Integral coil supports domestic hot water in single-bath residential systems

Summary

The Thermo-Dynamics CWL85-110LE is engineered for professionals requiring a compact, cast iron boiler with integrated domestic hot water capability and flexible installation features. Its fully water-backed combustion chamber, ASME compliance, and multi-rate burner design make it a durable and adaptable solution for both new construction and replacement projects.