180306 Suburban Bruner Orifice (METRIC THREADS) #53

SF-25 25F (ABOVE SERIAL NO. 021206467) SF/SFVH-25Q/FQ

The Suburban 180306 Burner Orifice meters the correct LP gas flow into the burner tube on 25k BTU Suburban furnaces. Sized at #53, this orifice is calibrated for the SF‑25 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.

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

Key Features

• OEM Suburban #53 LP burner orifice

• Metric threads for late‑production SF‑25 platforms

• Provides correct gas flow for 25k BTU furnace families

• Ensures proper flame shape, ignition reliability, and combustion stability

• Brass construction for clean, consistent metering

• Direct‑fit replacement for metric‑thread burner assemblies

When Technicians Replace This Orifice

• Yellow, lazy, or unstable flame

• Soot buildup in burner or exhaust

• Furnace failing to ignite or lighting inconsistently

• Incorrect BTU output or weak heating

• Orifice clogged with debris or contamination

• Burner assembly updated to metric‑thread spec

Compatibility

SF‑Series Furnaces:

• SF‑25 (units above serial no. 021206467)

• SF‑25F (units above serial no. 021206467)

• SF‑25Q

• SF‑25FQ

SFVH‑Series Furnaces:

• SFVH‑25Q

• SFVH‑25FQ

This is the correct OEM metric‑thread #53 orifice for all models listed above.