Best Hot Water Tank Burner Assemblies for Replacement
The best hot water tank burner assembly is the one that matches your heater’s brand, model, fuel type, and burner dimensions. These five options include A. O. Smith natural-gas and liquid-propane assemblies, plus Rheem kits in several configurations. Rheem’s listings specifically advise checking the water heater’s serial number before selecting a replacement. Use the product name and specifications as a starting point, then confirm the exact part number against your heater’s documentation or manufacturer.
| Product | Best For | Key Detail |
|---|---|---|
| A. O. Smith 100112342 | Natural-gas replacements | 16-inch assembly; #37 orifice |
| A. O. Smith 100094001 | Specified A. O. Smith repairs | Natural-gas assembly |
| Rheem SP45034 | Rheem heater owners matching the part | Kit includes replacement parts |
| Rheem SP43285 | Matching 40-inch assemblies | 40-inch kit |
| Rheem SP43282 | Matching 16-inch assemblies | 16-inch kit |
A. O. Smith 100112342 Natural-Gas Burner
This A. O. Smith assembly is listed as a final natural-gas burner with a 16-inch size and a #37 orifice. It is best for buyers whose heater’s required replacement part matches those specifications. The stated fuel type, length, and orifice make it easier to compare with the existing assembly or parts documentation.
Why it was selected: The listing provides more identifying details than a generic burner assembly listing. Check before buying: The product data does not identify compatible heater models, so verify the part number and specifications for your tank. Do not choose it for a liquid-propane heater based on the listing provided.
A. O. Smith 100094001 Natural-Gas Assembly
The A. O. Smith 100094001 is identified as a final natural-gas burner assembly. It is best for buyers who have confirmed that this exact part number is specified for their water heater. The provided product details do not state burner length or orifice size, so those characteristics should not be assumed from another A. O. Smith assembly.
Why it was selected: It gives A. O. Smith owners a distinct natural-gas replacement option when the heater’s parts information calls for this number. Check before buying: The listing details supplied here do not show model compatibility or dimensions. Confirm both with the heater’s documentation before ordering.
Rheem SP45034 Burner Assembly Kit
The Rheem SP45034 kit is described as containing an ignitor pilot flame and the parts needed to replace a burner assembly. The listing says the assembly generates heat for the water heater tank and advises searching by water-heater serial number to select the correct burner. It is best for Rheem owners whose serial-number lookup confirms this part.
Why it was selected: The kit description covers the burner replacement components and emphasizes serial-number verification. Check before buying: The provided details do not state burner length or fuel type. Confirm those requirements for your exact heater rather than assuming this kit fits.
Rheem SP43285 40-Inch Burner Kit
This Rheem kit is specifically described as a 40-inch burner assembly. Its listed features include an ignitor pilot flame and replacement parts for the burner assembly. Choose it if your heater’s required part matches SP43285 and the 40-inch specification. The listing says to use the water heater’s serial number to confirm the correct replacement.
Why it was selected: The stated length helps buyers distinguish it from Rheem’s 16-inch option. Check before buying: A 40-inch specification alone does not establish compatibility. Verify the serial number and exact part number before ordering.
Rheem SP43282 16-Inch Burner Kit
The Rheem SP43282 is described as a 16-inch burner assembly kit for a hot water tank. The listed kit includes OEM replacement parts and an ignitor pilot flame. It is best for Rheem owners whose heater’s serial-number lookup confirms SP43282 and whose required assembly is 16 inches.
Why it was selected: Its stated size makes it a clear comparison with the 40-inch SP43285 kit. Check before buying: Do not select it based on length alone; the listing advises checking the water heater’s serial number to verify the burner.
Buying Guide: How To Choose A Water Heater Burner Assembly
Which details should you match?
Start with the water heater’s model and serial number, then check the specified replacement part number. Compare the manufacturer, fuel type, burner length, and orifice details when available. A burner that appears similar may not be the correct assembly for your heater.
Does fuel type matter?
Yes. The A. O. Smith 100112342 and 100094001 listings identify natural gas. The supplied product data does not identify fuel type for the Rheem kits. Confirm your heater’s fuel and the replacement part’s requirements before purchase; do not treat natural-gas and propane assemblies as interchangeable.
How should you compare burner length?
The listed Rheem SP43282 is 16 inches, while the SP43285 is 40 inches. The A. O. Smith 100112342 is also listed as 16 inches. Compare these measurements with your heater’s specified part, but use the full part number and serial-number lookup—not length alone—to confirm fit.
Should you choose a kit or a burner assembly?
A kit may include additional replacement parts. Rheem’s SP45034, SP43285, and SP43282 descriptions mention kit components, including an ignitor pilot flame. The A. O. Smith listings provide burner identification details but do not describe included kit contents. Check the listing and heater documentation to determine which parts are needed.
Frequently Asked Questions
How do I find the right burner assembly for my water heater?
Use your heater’s model and serial number to identify the specified replacement part, then confirm the part number and relevant fuel and size details.
Can I use a 16-inch burner instead of a 40-inch burner?
Do not substitute based on appearance or convenience. The specified part number and heater information must confirm the correct assembly.
Is the A. O. Smith 100112342 for propane?
No. Its supplied description identifies it as a natural-gas assembly with a #37 orifice. Verify your heater’s fuel type before ordering.
Do the Rheem kits include an ignitor pilot flame?
The supplied descriptions for the SP45034, SP43285, and SP43282 mention an ignitor pilot flame. Confirm the listing details for the exact kit you select.