Active Protection: Monitors voltage and current in real-time to shut down the compressor before thermal or electrical damage occurs

Key Benefits Direct OEM Compatibility: Engineered specifically for the Honeywell DR4500 Truline series

maintaining safe and efficient burner operation during the ignition sequence

preventing common furnace pressure switch stuck open faults and system lockouts

The mode is determined by the internal jumper settings (J2)

Resideo L4006A1009 Aquastat Controller 321894-709 Active Protection: Monitors voltage andThe Resideo L4006A1009 Aquastat Controller is a professional grade immersion temperature controller designed for precise regulation in hydronic heating systems, storage tanks, and boilers. This high or low limit aquastat utilizes a 3 8" x 2 7 8" copper sensing bulb to monitor liquid temperatures between 100F and 240F. Featuring internal SPST contacts that break on temperature rise, this unit is engineered for reliable safety shut off or cycling