The Johnson Controls A11D-5 is a professional-grade low temperature cutout freezestat designed for critical freeze protection in HVAC systems

Standardized Wiring: Equipped with standard lead lengths for fast connection to the low voltage control board

this replacement is usually the solution

if not purged via the thermostatic vent

Lochinvar & A.O. Smith 100167804 Board 340793-762 The Johnson Controls A11D-5 isThe Lochinvar & A. O. Smith 100167804 Integrated Control Board is the primary OEM replacement part for the Armor AW400 condensing water heater series. As a veteran grade HVACR control module, this board manages the critical sequence of operation, including the 10 second prepurge cycle, spark to flame trial for ignition, and continuous flame rectification. It acts as the master processor for ignition control and temperature regulation, ensuring the