Williams 3003822 Wall Furnace

The Williams 3003822 is a professional-grade 30,000 BTU direct vent wall furnace designed for high-efficiency zone heating in residential and light commercial applications. As a direct replacement for models 3003612 and 3003622, this natural gas unit features a sealed combustion chamber that pulls oxygen directly from the outdoors, preserving indoor air quality and preventing back-drafting. With a 66% AFUE rating and a 21,000 BTU output, it provides reliable off-grid heating via a millivolt ignition system that requires no external electricity—making it a staple for contractors handling garage, workshop, or basement retrofits. The low-profile wall heater design 32-1/2" wide and 10-1/4" deep allows for space-efficient mounting through exterior walls up to 9" thick using the included vent kit. Its ceramic-coated combustion chamber and heavy-duty cast iron burners ensure long-term thermal transfer performance under heavy duty cycles.

Key Benefits

• Power Outage Reliability: Millivolt control system operates without electricity, providing consistent heat during grid failures.
• Enhanced Safety: Sealed combustion technology prevents carbon monoxide or soot from entering the living space.
• Simplified Installation: Comes standard with a complete rear vent kit and a matchless pilot igniter for faster job-site turnarounds.
• Small Footprint: Space-saving cabinet design integrates easily into tight floor plans without sacrificing 30K BTU capacity.
• Proven Compatibility: Direct drop-in replacement for legacy Williams furnace series 3003612 and 3003622.

Common Questions

Can I convert this unit to Liquid Propane (LP) in the field?
Yes, while this model is factory-configured for natural gas, it can be converted using the appropriate Williams LP conversion kit (Part #8927) by a licensed technician.

Does this unit include a blower for better air circulation?
The base model is a gravity-fed convection heater. For increased heat distribution, an optional 115V blower (Part #2302) can be installed, though it will require a standard electrical outlet.

What is the maximum wall thickness for the standard vent kit?
The included venting accommodates walls up to 9 inches thick. For deeper wall assemblies, 15-inch or 24-inch vent extensions are available as separate accessories.

This item must ship via truck. Please contact us for freight quote.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.