{"product_id":"blower-vacuum-switch","title":"Hayward Blower Vacuum Switch","description":"\u003cp\u003eThe Hayward FDXLBVS1930 is the blower vacuum switch for Universal H-Series Low NOx pool and spa heaters and the ASME versions, covering models H150FD, H200FD, H250FD, H300FD, H350FD and H400FD. It is the genuine Hayward part.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhat it proves\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eBefore the heater is allowed to ignite, it has to know the combustion blower is really moving air. The vacuum switch is what confirms that. It reads the pressure the blower creates and closes a contact, and only then does the ignition sequence continue.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eThe fault it causes\u003c\/strong\u003e\u003c\/p\u003e\u003cp\u003eWhen the switch fails, or the small hose that feeds it is cracked or plugged, the heater will start its blower and then lock out without firing. Before condemning the switch, check that hose and look for a restriction in the vent, because a blocked flue produces the same symptom. Once the switch itself is proven faulty it gets replaced, not bypassed; it is part of the safety chain that keeps the heater from firing into a dead blower.\u003c\/p\u003e","brand":"Hayward","offers":[{"title":"Default Title","offer_id":48625772462292,"sku":"HAY-151-0021","price":50.46,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0801\/9568\/2516\/files\/default_100af5ed-592e-4cf0-9a8a-8b9b932de2d5.jpg?v=1788692056","url":"https:\/\/www.activepoolsupply.com\/products\/blower-vacuum-switch","provider":"Active Pool Supply","version":"1.0","type":"link"}