Aaon P90790 Speed Control 30067439-890 or heat-related scale buildup on

or heat-related scale buildup on the internal contacts are common failure points in older units

it withstands the thermal cycling demands of high-efficiency furnaces and boilers

This switch monitors differential air pressure to confirm fan operation or filter loading

As a dual-function diagnostic instrument

this is an open fuse link

Aaon P90790 Speed Control 30067439-890 or heat-related scale buildup onThe Aaon P90790 Speed Control is a critical OEM Hoffman motor speed controller engineered for precise regulation of alternating current (AC) induction motors within Aaon HVAC systems. Designed for field technicians who demand exact performance, this 230V motor speed control utilizes a phase control method to modulate voltage, ensuring optimal airflow management in combustion air blowers. Built to interface with Permanent Split Capacitor (PSC) or