When performing a Lennox HVAC control board troubleshooting procedure

and VR8215 series combination gas controls

In standard configurations

provided the 7-11" WC spring range matches the appliance manifold requirements

preventing flue gas spillage by disabling the burner if the differential pressure falls below the safety threshold

Carrier P283-0380 Fan Relay 320735-701 When performing a Lennox HVACThe Carrier P283 0380 Fan Relay is a specialized electromechanical switch designed for high cycle reliability in residential and commercial HVAC units. Featuring a 24V coil, this relay serves as the critical interface between low voltage thermostat controls and high voltage blower motor circuits. The SPNO SPNC (Single Pole Normally Open Single Pole Normally Closed) configuration provides dual circuit flexibility, allowing for the switching of