The GH model is the current manufacturer update for the GF series

Smith 100133547 Flange Gasket is a critical high-temperature seal designed for commercial water heaters and boiler systems

Flexible Installation: Dual-mount design with a 1/2-inch NPT threaded hub and steady foot mount for various enclosure types

specifically within the SC

Resideo L8148E1299 Aquastat Relay Els PW 17895 The GH model is theThe Resideo L8148E1299 is a technical grade high limit Aquastat relay designed for immersion type hydronic systems. This 120Vac controller effectively combines system safety with operational switching, managing both the burner and circulator motors. Engineered with a vertical mount configuration, it provides a high limit operating range of 180F to 240F with a 15 degree fixed differential. This ensures consistent thermal cycling and reliable system