Lochinvar & A.O. Smith 100074280 Limit Switch 319848-301 and PGMD series

and PGMD series

This Modine unit heater motor features a 5-inch diameter casing and is typically mounted via four studs on the shaft end (4-5/8" bolt circle)

it integrates seamlessly with thermostatic radiator valves (TRVs) to provide localized room temperature control

Whether you are performing a new installation or replacing a worn Honeywell 315781 ball joint

Lochinvar & A.O. Smith 100074280 Limit Switch 319848-301 and PGMD seriesThe Lochinvar & A. O. Smith 100074280 High Limit Switch is a critical safety component engineered to provide thermal protection in high efficiency heating systems. Designed as a genuine OEM replacement part, this switch monitors the internal temperature of the heat exchanger or burner door to prevent unsafe operating conditions. If temperatures exceed the factory defined safety threshold, the 100074280 triggers an immediate system lockout to mitigate