The high-energy spark igniter electrode is constructed from durable materials to withstand extreme thermal cycling and prevent nuisance shutdowns

code-compliant solution for hot water space heating reliability

minimizing lockout cycles even in demanding high-demand environments

a single pointer on the internal scale indicates the current cutout value

Neptronic AC2-B Auxiliary Switch 321894-708 The high-energy spark igniter electrodeThe Neptronic AC2 B is a high performance auxiliary switch designed for seamless integration with Neptronic BT, BTM, and BTX series actuators. Built to handle double pole, double throw (DPDT) configurations, this unit provides precise remote status feedback and control for HVAC dampers and valve actuators. As the engineered replacement for the BT180 and compatible with BT160 footprints, it secures reliable end switch signaling within building