Heil Quaker ICP 1175977 Main Orifice

The Heil Quaker ICP 1175977 #44 Main Orifice is the OEM number 44 drill-size main burner orifice for ICP, Heil and Tempstar gas-fired heating equipment — a threaded brass gas spud that does one small job exactly right. The orifice is the calibrated opening that meters gas into the burner from the gas manifold, and together with manifold pressure it sets the burner input and the flame quality of the whole heat cycle. A #44 drill size opening measures 0.0860 inch, so a little scale, corrosion or a careless reaming is enough to change how much gas reaches the burner. This is the factory number, 1175977, so you keep the original OEM sizing instead of guessing at an aftermarket equivalent.

The part is a fixed orifice (also called a spud) that threads into the manifold ahead of a main burner. The photo shows a brass body with a male pipe-thread end and a hex section behind the threads for a socket or wrench, with the metering bore running through the center. Gas flow through any orifice rises with the square root of the pressure drop, and gases with different specific gravity need different orifice sizes — which is why natural gas and propane (LP) orifices are not interchangeable without the correct conversion kit. Always confirm the gas type and input rating on the unit rating plate against the size stamped on the orifice you are replacing.

When an orifice goes bad, the burner tells you. A partly blocked or damaged spud shows up as yellow, lazy or lifting flames, soot, delayed ignition, rollout or a flame sensor that drops out mid-cycle, while an enlarged or drilled-out orifice over-fires the burner. Check manifold pressure first, inspect the orifice with a light, and never ream or drill a spud to clean it — replace it with the correct size. Install it with full thread engagement, snug it up without over-torquing the manifold threads, and leak-test with approved solution before putting the unit back in service. On a manifold with several burners, match every position to the size on the rating plate. Related ICP numbers in the same run include the 1175976 gas valve, the 1175974 ignitor assembly and the 1175973 flame sensor, and ICP also lists a multi-piece #44 kit under 1186372.

Key Benefits

• OEM #44 Sizing: The factory 1175977 orifice holds the original 0.0860 inch bore, so burner input and flame pattern stay where the manufacturer set them.
• Brass Spud Construction: A brass body with a male pipe thread and hex section installs and removes cleanly with standard tools.
• Accurate Gas Metering: A true calibrated orifice restores steady blue flame combustion that a blocked or reamed spud cannot deliver.
• Direct Factory Replacement: Ordered by the ICP part number 1175977, so you are not matching a drill size by eye on a hot manifold.

Common Questions

• What size is the 1175977? It is a #44 drill size main orifice, which is 0.0860 inch in diameter.
• Is it for natural gas or propane? The #44 is the drill size only. Confirm the gas type and input rating on the rating plate and compare the size stamped on your old orifice; use the proper LP or natural gas conversion kit if the fuel is being changed.
• How many do I need? A furnace uses one orifice per burner, so count the burners on the manifold and order that many, matching the size called for on the rating plate.

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.