180308 Suburban Bruner Orifice (METRIC THREADS) #51

SF-35 35F (ABOVE SERIAL NO. 021206467) SH-35 35F SF/SFVH-35Q/FQQ

The Suburban 180308 Burner Orifice meters the correct LP gas flow into the burner tube on 35k BTU Suburban furnaces. Sized at #51, it is calibrated for the SF‑35/SH‑35 family’s BTU output and ensures proper ignition, stable flame shape, and clean combustion. The metric thread design is used on later‑production furnaces and all Q/FQ variants.

Correct thread type is essential—using a standard‑thread orifice in a metric burner assembly can cause cross‑threading, gas leaks, or improper seating.

Key functions this orifice supports

• Maintains correct LP gas flow for 35k BTU furnace platforms

• Ensures stable flame shape and clean combustion

• Supports reliable ignition and consistent heating output

• Prevents soot, yellow flames, and over‑ or under‑firing

Compatibility

SF‑Series Furnaces:

• SF‑35 (units above serial no. 021206467)

• SF‑35F (units above serial no. 021206467)

• SF‑35Q

• SF‑35FQ

SFVH‑Series Furnaces:

• SFVH‑35Q

• SFVH‑35FQ

SH‑Series Furnaces:

• SH‑35

• SH‑35F

This is the correct OEM metric‑thread #51 orifice for all models listed above.