A.o. Smith 100108899 High Limit Switch 200F Manual Reset

Product Description

The A.O. SMITH 100108899 is a manual reset high limit switch assembly designed for venting applications on commercial water heaters. This switch monitors flue gas or exhaust temperatures and trips when temperatures exceed the rated threshold of 200 degrees F, shutting down the burner to prevent damage or unsafe conditions. Resetting requires a manual action, making it a positive-shutoff safety device. Installation is typically performed by licensed plumbers or HVAC technicians servicing commercial gas water heater systems.

This switch assembly is a direct replacement part for A.O. SMITH power direct vent water heater models. It is used in residential and light commercial applications where venting safety controls are required. The manual reset design ensures the unit does not restart automatically after a high-temperature event, requiring a technician to diagnose the root cause before returning the appliance to service.

Key Features

• Manual reset design requires deliberate technician action before restart after a trip event
• Rated trip temperature of 200 degrees F for venting overheat protection
• OEM replacement assembly for A.O. SMITH GPD and GPDX series water heaters
• Designed for venting circuit safety monitoring on gas water heater systems

Compatibility

Compatible with A.O. SMITH models GPD 40, GPD 50, GPDX 50, and GPD 75.

Installation Notes

Installation should be performed by a licensed plumber or qualified HVAC technician. Shut off gas supply and disconnect electrical power to the water heater before beginning any service work. Follow applicable local codes and manufacturer service documentation when replacing limit switches or venting safety assemblies. Do not bypass or jumper the switch under any circumstances.

Technical Specifications

• Trip Temperature: 200 degrees F
• Reset Type: Manual Reset
• Application: Replacement Part

Standard Information

• Brand: A.O. SMITH
• Manufacturer Part Number: 100108899