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Williams 4505622A

45,000 BTU Floor Furnace, 70% Efficiency, Natural Gas

(7 Reviews)


Williams floor furnaces use no above-the-floor room space as it unobtrusively and efficiently circulates warm air, and does it without the aid of a blower. These models are fitted with an automatic floor-register grill temperature control and non-electric pilot to ensure continuous heat - even during power outages.

Floor furnaces operate very quietly. These models offer affordable solutions for limited-space floor plans, remodels, remote cabin locations and new construction.

In order to operate on LP gas, a separate conversion kit must be purchased. (Please see the Accessories tab above.) Please read this Important Safety Notice.

Design Features

  • No electricity required
  • "Matchless" pilot ignitor
  • Easy installation
  • Combustion chamber lifts out for easy servicing
  • Long-life and quiet heavy-duty burner
  • Wall-mounted thermostat included
  • Natural and propane gas models (LP Conversion kit available)
  • Automatic temperature and safety controls
  • Resettable vent-limit safety switch

Heating Capacity

The amount of heat, rated in BTUs that the item can produce.

Heating Capacity
45000 BTU
Effective Heating Capacity (BTUs)
Efficiency (% AFUE)

The percentage of energy converted into output by the unit. The remaining percentage is lost during the conversion process. The higher the efficiency, the lower the operational cost.

Efficiency (% AFUE)
57 %
Thermal Efficiency

The percentage of the heat generated by combustion that goes into heating. The remaining percentage goes out the flue. The higher the efficiency rating, the lower the cost of operation.

Thermal Efficiency
70 %
Equipment Type
Floor Furnace
Floor Opening
24.5 W x 32.37 D inches
Flue Pipe Diameter

This refers to the size of the flue pipe needed, and not necessarily the actual connection size on the furnace. Flue diameter is based on length of run and number of elbows used. Please read the installation instructions carefully to ensure correct diameter flue size for your application.

Flue Pipe Diameter
Product Weight
147 lbs
Meets CSA Standards

Canadian Standards Association

Meets CSA Standards
Meets Canadian OEE Standards

Standards established by Canada's Office of Energy Efficiency.

Meets Canadian OEE Standards
24 Inches
32 Inches
28 1/2 Inches
Heat Exchanger Warranty
10 Years
Parts Warranty
1 Years