Lochinvar 100170550 Outlet Sensor High Limit Replacement 100208547 TST20022

Product Description

The Lochinvar 100170550 is an outlet sensor high limit designed for use in Lochinvar water heaters and boiler systems. This component monitors the water temperature at the outlet of the heat exchanger or storage tank. When the outlet temperature exceeds a safe threshold, the high limit sensor triggers a safety response to protect the system from overheating. HVAC technicians and plumbers rely on this type of sensor to maintain safe and efficient operation in residential and commercial hot water systems.

The outlet sensor high limit plays a critical role in the control circuit of a Lochinvar unit. It sends a temperature signal to the control board, which uses that data to regulate burner operation. If the measured temperature climbs too high, the control board shuts down the burner to prevent damage to the heat exchanger, piping, and connected equipment. Replacing a faulty high limit sensor restores accurate temperature monitoring and keeps the safety system fully functional.

This part is a direct replacement for Lochinvar part numbers 100208547 and TST20022. Using an OEM-compatible replacement ensures proper fit, correct resistance or voltage output, and compatibility with the existing control board. Generic sensors may not meet the same calibration standards, which can lead to nuisance shutdowns or, worse, delayed safety responses. Choosing the correct replacement part by MPN is the standard practice for service technicians working on Lochinvar equipment.

Common applications include Lochinvar Knight boilers, Copper-Fin water heaters, and other Lochinvar residential and light commercial units that use outlet temperature sensing for high limit protection. If a unit is displaying a high limit fault code, failing to reach setpoint, or short cycling, the outlet sensor is one of the first components to test and replace during a service call.

• Outlet temperature sensor with high limit function for Lochinvar water heaters and boilers
• Direct replacement for Lochinvar part numbers 100208547 and TST20022
• Restores accurate temperature monitoring and high limit safety protection

Product Highlights

The Lochinvar 100170550 outlet sensor high limit is a key safety component that monitors outlet water temperature and protects the system from overheating. It is a verified replacement for cross-reference part numbers 100208547 and TST20022, making it a straightforward drop-in repair part for qualified service technicians.

Product Information

Standard Information

• Brand: LOCHINVAR
• Manufacturer Part Number: 100170550

Technical Specifications

• Component Type: Outlet Sensor High Limit
• Cross Reference Part Numbers: 100208547, TST20022
• Compatible System Types: Water Heaters, Boilers
• Function: Monitors outlet water temperature and triggers high limit safety response