Trane SEN1951 Flame Sensor 326010-701 the A421 series represents the

the A421 series represents the next generation of PENN temperature controllers

If the contacts have fused

the bimetallic strip in the Lennox limit switch may be fatigued

preventing costly leaks and maintaining precise control within your HVACR systems

Trane SEN1951 Flame Sensor 326010-701 the A421 series represents theThe Trane SEN1951 Flame Sensor (also identified as SEN01951) is a critical OEM replacement part engineered to maintain precise flame rectification within residential and commercial furnace burners. This furnace flame sensor operates by detecting the presence of a microamp signal generated during combustion. If the HVAC control board fails to receive this signal, it immediately terminates the gas valve cycle to prevent hazardous gas accumulation.