Anti-Siphon Valves (Air Gaps)

Home inspectors in California should comment on the lack of an air gap in the kitchen, and in the instance of a newer installation usually results in some controversy. I will try to explain the need for this device as easy as possible. An air gap is a device that is usually chrome in color, (other colors are available), that is mounted on the top of the counter near the kitchen sink and facilitates proper dainage of the dishwasher. The lack of this device creates a potential health hazard due to contaminates that originate in drain pipes, drain trap, or the garbage disposal from siphoning back into the dishwasher. Even though it may be a top of the line appliance, and some manufaturer’s installation instructions may state that the appliance has a built in anti-siphon device or integral backflow device, and an additional air gap may not be necessary, California does require this device.

"UPC 807.4 No domestic dishwashing machine shall be directly connected to a drainage system or food waste disposer without the use of an approved dishwasher airgap fitting on the discharge side of the dishwashing machine. Listed airgaps shall be installed with the flood level (FL) marking at or above the flood level of the sink or drainboard, whichever is higher".

 Anti-Siphon Valve

3 Responses to “Anti-Siphon Valves (Air Gaps)”

  1. Greg Dyer says:

    We have an anti-siphon valve as you describe and we have been told it is not functioning properly. When the DW is running, sounds like when draining, wather flows out of the anti-siphon valve into the sink. I replaced the part with one form Lowes, and it still does it. Would you please tell me what is going wrong and how to fix it? Thanks

  2. Hi there, I just come across your blog browsing on Google as I am researching some info on dishwashers. Looks like a cool blog so I bookmarked you and I will come back tomorrow to have a more detailed read when i have more time. Great site!.

  3. admin says:

    Most likely the hose that attaches to the garbage disposal is clogged, and will need to be cleaned. Simply disconnect the hose at the disposal, clean it out and re-attach.

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