Viessmann 7820148 Sensor L99H008 this unit modulates fan speed

this unit modulates fan speed based on direct pressure input

The on/off control move the damper fully open or closed

By utilizing a genuine Lennox furnace pressure switch

High-Efficiency Output: The 825 RPM motor provides optimal CFM across the condenser coil to manage head pressure effectively

Viessmann 7820148 Sensor L99H008 this unit modulates fan speedThe Viessmann 7820148 Sensor serves as the primary outdoor temperature sensor for weather responsive heating systems, enabling critical compensation logic for gas condensing boilers. Engineered for high accuracy ambient monitoring, this NTC thermistor ensures the Vitotronic 200 and 300 control units can dynamically adjust the heating curve based on real time meteorological data. By integrating this OEM replacement part, technicians can resolve common