Williams 8A143 Natural Gas High Altitude Orifice Conversion Kit for 30,000 BTU Direct Vent Furnace

The Williams 8A143 is a high altitude orifice conversion kit designed for the Williams 30,000 BTU Natural Gas Direct Vent Gravity Furnace (model 3003822). This kit enables safe and efficient furnace operation at elevations beyond the standard sea-level rating by replacing the factory orifice with one sized for the appropriate altitude range.

Standard Williams wall furnaces are rated for operation from 0 to 2,000 feet above sea level. When installed at higher elevations, the air-to-fuel ratio changes, requiring a correctly sized orifice to maintain proper combustion. This kit contains all necessary orifices to match your specific installation altitude.

Included Orifices & Elevation Ranges:

• P090541 — 2,001 ft to 4,000 ft above sea level
• P090542 — 4,001 ft to 6,000 ft above sea level
• P090545 — 6,001 ft to 8,000 ft above sea level

Key Features:

• Engineered specifically for the Williams 3003822 30,000 BTU Natural Gas Direct Vent Gravity Furnace
• Covers high altitude installations from 2,001 ft up to 8,000 ft above sea level
• Includes three precision-sized orifices — one for each elevation range
• Ensures safe combustion and consistent heating performance at elevated installations
• OEM Williams Furnace Company replacement part

Select the correct orifice for your installation elevation and replace the existing burner orifice per the furnace installation manual. Only one orifice is installed at a time; the remaining orifices are retained for reference or future use.