Hayward H-Series Blower Vacuum Switch, IDXLBVS1930

Hayward IDXLBVS1930 is the blower vacuum switch for H-Series pool heaters. It is the genuine Hayward part.

What it is for

Before an H-Series heater lights, the combustion blower has to be moving air. The vacuum switch is what proves it. It senses the suction the blower produces and closes a contact; only then does the control carry on to ignition. If it never closes, the heater stops there rather than putting gas to a burner with no airflow, which is exactly what the interlock is for.

Diagnosing it

The classic symptom is a heater that starts up, runs its blower and then locks out without firing. Before condemning the switch, check the small sensing hose between it and the blower housing for cracks, kinks or soot, and confirm the blower wheel spins freely. Those faults look identical from the control panel, and both are cheaper to fix.