including direct acting (DA) and reverse acting (RA) models

and S3 (or +

you must use the correctly sized LP orifice (typically part 560-528-998) to prevent hazardous combustion conditions

Common issues include restricted return airflow

coffee residue

Lennox 34M76 Pressure Switch including direct acting (DA) andThe Lennox 34M76 Pressure Switch is a critical safety component designed for high efficiency condensing gas furnaces. Engineered with an actuation set point of . 86" WC (Water Column) and a reset point of 1. 01" WC, this Single Pole Single Throw (SPST) switch ensures the inducer motor establishes a proper vacuum before the ignition sequence begins. Designed for a 1 4" barb connection, it provides a reliable pneumatic seal to prevent the furnace from