Orifices

Bradford White water heater orifices are precision-drilled gas metering components that control how much natural gas or liquid propane flows to the burner or pilot assembly in Bradford White residential and light-duty commercial water heaters. The bore diameter of each orifice is calibrated specifically to the fuel type, the water heater's BTU input rating, and the installation elevation. Bradford White uses a numbered orifice system across its residential product line, with the 234-41034 series covering natural gas main burner orifices and the 234-47064 series covering LP gas main burner orifices. Pilot orifices follow a separate numbering scheme under the 234-46502 series. Installing the wrong orifice bore can result in incomplete combustion, sooting, or insufficient heat output, making exact part number matching against the water heater's model number a required step before replacement.

KEY SUBCATEGORIES / PRODUCT TYPES

Natural gas main burner orifices for Bradford White water heaters fall within the 234-41034 series, with the specific suffix number determining the bore size and elevation rating. Standard-altitude natural gas orifices are rated for installations from 0 to 2,000 feet. Common standard-altitude orifice numbers found across Bradford White residential models include #21 (SKU 234-41034-21), #27 (SKU 234-41034-27), #31 (SKU 234-41034-31), #32 (SKU 234-41034-32), #33 (SKU 234-41034-33), #35 (SKU 234-41034-35), #36 (SKU 234-41034-36), #38 (SKU 234-41034-38), and #52 (SKU 234-06016-52). The orifice number corresponds to a specific bore diameter, with higher numbers indicating smaller bores. Matching to the water heater model's official parts list from Bradford White documentation is the only reliable way to confirm which orifice number applies to a given unit.

LP gas main burner orifices for Bradford White water heaters fall within the 234-47064 series. LP orifices carry smaller bore diameters than their natural gas counterparts for the same BTU input because propane is delivered at higher pressure and contains more energy per cubic foot. Common LP main burner orifice part numbers found across Bradford White residential models include the stamped LP #51 (SKU 234-47064-51), #52 (SKU 234-47064-52), #53 (SKU 234-47064-53), #54 (SKU 234-47064-54), and #60 (SKU 234-47064-60). Standard LP orifices are rated for 0 to 2,000 feet elevation. Separate high-altitude LP orifice SKUs apply at elevations above 2,000 feet, and those part numbers differ from standard-altitude parts even within the same 234-47064 series.

High-altitude orifices are model-specific Bradford White parts required when a water heater is installed above 2,000 feet elevation. At higher elevations, reduced air density changes the combustion air-to-fuel ratio, and a standard orifice can produce a rich, sooty flame or fail to deliver rated BTU output. Bradford White parts lists break altitude ranges into tiers: 2,001 to 5,000 feet, 5,001 to 8,000 feet, and 8,001 feet and above for older model families, or a consolidated 0 to 7,000 foot high-altitude orifice for some newer residential and power-vent models. The natural gas high-altitude orifice 234-41034-27 (SKU 234-41034-27) appears across multiple Bradford White power-vent and atmospheric-vent model families for installations up to 7,000 feet. The LP gas high-altitude orifice 234-47064-52 (SKU 234-47064-52) covers 0 to 7,000 foot installations across multiple LP residential models. Always confirm the elevation range and model suffix against Bradford White's current parts list documentation before ordering a high-altitude orifice.

Pilot orifices are the separate, smaller-bore metering components that feed the standing pilot flame in Bradford White water heaters using the ICON System and similar millivolt-powered gas control platforms. Bradford White pilot orifices fall within the 234-46502 series. The natural gas pilot orifice 234-46502-05 (SKU 234-46502-05), with a bore diameter of .0156 inches, appears as the standard service replacement pilot orifice across a wide range of Bradford White residential natural gas models including M-I series, RG2 series, and DS series atmospheric and power-vent units. The LP gas pilot orifice 234-46502-02 (SKU 234-46502-02), with a bore diameter of .010 inches, is the standard LP pilot orifice appearing across multiple Bradford White FVIR-equipped LP models. Pilot orifice replacement is typically indicated when the pilot flame is weak, unstable, or fails to hold the thermocouple or thermopile at operating voltage.

BUYING GUIDE / HOW TO CHOOSE

Choosing the right Bradford White orifice replacement starts with a single source of truth: the official Bradford White parts list for the specific water heater model number. Bradford White organizes its replacement parts documentation by model family, and the parts lists explicitly call out which orifice SKU applies to natural gas vs. LP, standard altitude vs. high altitude, and specific model variants within a series. The model number on the water heater's data plate, combined with the installation altitude in feet, provides the two variables needed to pull the correct parts list entry. Standard natural gas orifices in the 234-41034 series are rated for 0 to 2,000 feet. High-altitude versions of the same orifice carry different suffix numbers and apply at elevations starting at 2,001 feet, with further distinctions above 5,000 feet and 7,000 feet depending on the model family. For LP models, the 234-47064 series follows the same altitude-tiered structure. Pilot orifice replacement follows the same model-matching process, with fuel type determining whether the 234-46502-05 (NG, .0156" bore) or the 234-46502-02 (LP, .010" bore) applies. Trying to deduce the right orifice from bore size alone, without confirming against the parts list, can result in an orifice that fits the thread but delivers the wrong fuel flow rate for the specific model's BTU rating.

FAQs

What does the orifice number mean on a Bradford White water heater part?

Bradford White orifice numbers follow a series-plus-suffix format that encodes both the orifice family and the bore size. The 234-41034 series covers natural gas main burner orifices, and the suffix number after the hyphen (for example, -33, -36, -38) corresponds to a specific bore diameter calibrated for that model's BTU input. Higher suffix numbers generally indicate smaller bores. The 234-47064 series follows the same structure for LP gas orifices. Matching the full part number, not just the series prefix, against the Bradford White model-specific parts list is necessary to confirm the correct replacement.

What's the difference between a standard Bradford White orifice and a high-altitude orifice?

The difference between a standard Bradford White orifice and a high-altitude orifice is bore diameter, which is adjusted to compensate for reduced combustion air density at elevation. Standard orifices in the 234-41034 (natural gas) and 234-47064 (LP) series are rated for 0 to 2,000 feet. At elevations above 2,000 feet, a different orifice with a smaller bore restricts gas flow to maintain the correct air-to-fuel ratio given the thinner air. Bradford White parts lists identify high-altitude orifices separately from standard orifices, with distinct SKUs for each elevation tier. Installing a standard-altitude orifice at high elevation can result in a rich flame, sooting, and reduced heating efficiency.

What Bradford White pilot orifice fits most residential natural gas water heaters?

The Bradford White natural gas pilot orifice 234-46502-05 (SKU 234-46502-05) is the standard service replacement pilot orifice for natural gas across a wide range of Bradford White residential water heater models, including M-I series, RG2 series, and DS series atmospheric and power-vent units. The 234-46502-05 has a bore diameter of .0156 inches. For LP gas models, the LP pilot orifice 234-46502-02 (SKU 234-46502-02), with a .010 inch bore, is the standard replacement across FVIR-equipped LP residential models. Confirming against the water heater model's parts list documentation before ordering is still recommended, as pilot orifice part numbers can vary by model family and control type.

Can the same Bradford White orifice be used for both natural gas and LP water heaters?

Bradford White natural gas and LP orifices aren't interchangeable. Natural gas orifices in the 234-41034 series carry larger bore diameters sized for natural gas pressure and energy content, while LP orifices in the 234-47064 series carry smaller bores calibrated for propane's higher pressure and BTU density. Installing an LP orifice on a natural gas model can starve the burner of fuel; installing a natural gas orifice on an LP model can create an over-rich combustion condition. Fuel type is a required input when selecting any Bradford White orifice replacement, and the parts list for the specific model will confirm which series and suffix number applies for each fuel.

Where can the correct Bradford White orifice part number be found for a specific water heater model?

The correct Bradford White orifice part number for a specific model is found in the official Bradford White Residential Gas Replacement Parts List documentation for that model family. Bradford White organizes parts lists by model series and makes them available through docs.bradfordwhite.com. The water heater's data plate carries the model number needed to identify the applicable parts list. Once the parts list is located, the orifice section will specify the correct SKU for natural gas vs. LP, standard altitude vs. high altitude, and any model-specific variants. Ordering from the parts list rather than estimating by bore size is the reliable approach to confirming a correct fit.