A.o. Smith 100076305 Fkm O-ring Water Heater

Product Description

The A.O. SMITH 100076305 is an FKM (fluoroelastomer) O-ring used as a sealing component in A.O. Smith tankless water heater assemblies. FKM material provides strong resistance to high temperatures and chemical degradation, making it appropriate for hot water service environments. This O-ring maintains a pressure-tight seal at connection points within the unit, preventing water intrusion and maintaining system integrity. It is installed by licensed plumbers and HVAC technicians during routine maintenance, component replacement, or repair service on compatible A.O. Smith tankless models.

This O-ring is used across a wide range of A.O. Smith tankless water heater models in both natural gas (NG) and liquid propane (LP) configurations. It is a direct OEM replacement part, restoring factory seal performance when the original O-ring shows wear, cracking, or compression set. Compatible models span residential indoor, outdoor, and direct-vent installations across multiple product families.

Key Features

• FKM (fluoroelastomer) construction for high-temperature and chemical resistance in hot water applications
• OEM replacement part ensuring factory-spec fit and sealing performance
• Compatible with both natural gas and liquid propane tankless water heater variants
• Maintains pressure-tight seal at internal connection points to prevent leaks
• Covers a broad range of A.O. Smith tankless model configurations including indoor, outdoor, and direct-vent units

Compatibility

Compatible with the following A.O. Smith tankless water heater models: T-M50-ASME (LP), T-KJR (LP), TK-540P-PIH (LP), T-KJR2U-IN (NG), T-H3M-DV (NG), T-D2U-IN (NG), T-K4-OS (NG), T-M32 (NG), T-K3 (NG), T-H2-DV (NG), T-D2-IN (LP), T-M32-ASME (LP), T-H3M-OS (LP), T-KJR2-IN (LP), T-M32 (LP), T-K1S (LP), T-K3 (LP), T-M50 (LP), T-K4-IN (NG), T-K4-OS (LP), T-KJR2U-OS (NG), T-H3J-OS (NG), T-H3S-OS (NG), T-KJR2-OS (LP), T-H3-DV (LP), T-H2S-OS (LP), T-H3-DV (NG), T-H3S-DV (LP), T-H2S-DV (LP), T-H3-OS (NG), T-K3-OS (LP), T-M1 (NG), T-M32-ASME (NG), TK-510C-NI (NG), T-KJR2-OS (NG), TK-540P-NIH (NG), T-D2-OS (LP), T-M1 (LP), T-M50-ASME (NG), T-K3-SP (LP), T-K3-OS (NG), T-D2-IN (NG), T-D2U-OS (NG), T-KJR (NG), T-H3J-DV (LP), T-K2 (LP), T-K1S (NG), T-H3M-OS (NG), T-KJR2-IN (NG), T-M199 (LP), T-KD20 (LP), TK-540P-NEH (NG), T-H3S-DV (NG), T-H3-OS (LP), T-H3J-DV (NG), T-K4-IN (LP), T-H2-DV (LP), T-H2S-DV (NG), T-H2-OS (LP), T-M50 (NG), T-D2-OS (NG), T-K4U-IN (NG), T-H3J-OS (LP), T-K3-PRO (NG), T-K3-PRO (LP), T-K4U-OS (NG), T-H1 (NG), T-K2 (NG), T-H3M-DV (LP), TK-540P-PEH (LP), T-M199 (NG), T-H1 (LP), TK-310C-NI (NG), TK-110C-NI (NG), T-H2S-OS (NG), T-H3S-OS (LP), T-KD20 (NG), T-H2-OS (NG), T-K3-SP (NG).

Installation Notes

O-ring replacement should be performed by a licensed plumber or qualified service technician. Before beginning any service, shut off the water supply and disconnect power or gas to the unit per the manufacturer service documentation and applicable local codes. Inspect the seating surface for debris or damage before installing the new O-ring, and avoid using sharp tools that could nick the sealing surface or the O-ring itself. Do not over-compress the O-ring during reassembly.

Technical Specifications

• Part Type: O-Ring
• Material: FKM (Fluoroelastomer)

Standard Information

• Brand: A.O. SMITH
• Manufacturer Part Number: 100076305