Pentair AGS 150 Degree F | ETi 250 / ETi 400 Heater | 475985

Description

The Pentair AGS 150 Degree F (475985) is the OEM replacement 150°F automatic gas shut-off sensor for the Pentair ETi series pool and spa heaters.

⚠️ IMPORTANT: LICENSED PROFESSIONAL INSTALLATION REQUIRED
Gas and electrical heater components must be serviced by a licensed pool professional or qualified HVAC technician. Do not attempt to service gas or high-voltage components without proper certification.

This automatic gas shut-off (AGS) switch monitors heater temperature and interrupts the gas supply when the heater reaches 150°F, protecting the unit from thermal damage caused by restricted water flow, a blocked heat exchanger, or other fault conditions. Replacing a failed or out-of-tolerance AGS switch restores the heater’s thermal protection circuit to factory specification.

Specifications

Fits Into

Compatibility is based on Pentair parts documentation and available OEM records. This is not an exhaustive list. For certainty, verify the part number in your equipment’s manual or on the original part itself before ordering.

Pro Tip

Before ordering, confirm the trip temperature stamped or printed on your existing switch matches 150°F — the ETi series uses multiple AGS switches rated at different temperatures for different protection points within the heater. Installing a switch with the wrong trip temperature will cause nuisance shutdowns or, worse, leave the heater without adequate thermal protection at the correct threshold. Match the part number on the original component to 475985 before adding to cart.