Condensing Boiler

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Q85S click to zoom into photo of
  • Fully modulating pump combines with stainless steel heat exchanger to make this one of the more efficient units available
  • Optional 3-way valve available to eliminate the need for a pump for the indirect tank
  • Compact wall-mounted design saves space over traditional boilers
  • Super quiet operation
  • Outdoor reset function with sensor included
  • Plumbing kits with low-loss header included
  • Available in Natural Gas or Propane
  • Variety of venting options available
  • ASME accredit units

Width: 19.7 inches (500 mm)

Height: 26.8 inches (680 mm)

Depth: 15.2 inches (385 mm)


110 lbs (50 kg)

Gas Type

Natural Gas, Propane with conversion kit

Maximum Heating Capacity

78,000 BTU (23 kW)

Minimum Input

​Natural Gas: 17,000 BTU (5 kW)

Propane: 37,000 BTU (11 kW)

Maximum Input

​85,000 BTU (25 kW)

Maximum Input (Heating)

​85,000 BTU (25 kW)

Turn Down Ratio


DHW Activation Rate

Indirect Tank Compatible

Maximum DHW at 75°F ΔT

Indirect Tank Compatible

Maximum DHW at 41.7°C ΔT

Indirect Tank Compatible

AFUE Rating


Circulating Pump


Storage Capacity


Approved Venting Material

​Polypropylene, Stainless Steel, PVC, CPVC


​Standard Warranty (some restrictions apply):

Residential: 12-year on heat exchanger, 2-year on parts, 1-year on labor

Commercial: 5-year on heat exchanger, 2-year on parts, 1-year on labor


​Energy Star®, CSA, NB, IBR, ASME, H

Included in the Box

• Plumbing kit - includes pre-assembled low-loss header with isolation valves, PRV, boiler drain, temperature and pressure gauge, unions and insulation

• 3” (80 mm) twin pipe adapters for venting (PVC and PP)

• Wall mounting bracket

• Outdoor reset sensor

• 3/4” gas shut-off valve

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