Tekmar Controls 519 Thermostat 321042-401 the AFS-A air pressure sensing

the AFS-A air pressure sensing switch includes a 1/4" NPT female high-pressure inlet and a 1/8" NPT female low-pressure inlet

This comprehensive HVAC calibration kit replaces legacy M-232 sets

343314-75101 is the cross for 321894-401

this PSC motor (Permanent Split Capacitor) features 3-speed taps

this 1/2" NPT solenoid valve provides superior resistance to corrosion when handling aggressive media

Tekmar Controls 519 Thermostat 321042-401 the AFS-A air pressure sensingThe Tekmar Controls 519 Thermostat is a purpose built solution for precise radiant floor heating management in hydronic systems. This 24Vac 24Vdc one stage radiant heat thermostat utilizes advanced Pulse Width Modulation (PWM) technology to eliminate the temperature swings common in standard on off controls, ensuring consistent thermal mass stability. Engineered for versatility, it functions as a direct replacement for the legacy Tekmar 509 and