Backflow preventer on washing machine connections?

This house already had backflow preventers on the washing machine supply lines when we bought it, and we continued to use them.
They are roughly like this:
http://www.homedepot.com/h_d1/N-5yc1v/R-202560207/h_d2/ProductDisplay?langId=-1&storeId051&catalogId053
Now one of them is leaking, and I am wondering whether they are needed at all. What purpose do they serve? The washing machine is below ground level, if that matters.
Perce
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They are to prevent backflow from the washing machine to the domestic water supply if the supply pressure fails.
Remove them, clean them in CLR (or equal), replace the washers.
OR
Just replace them with new ones.
cheers Bob
cheers Bob
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Ooops! I forgot that washing machines have a built-in "air gap".
I'm not sure why they're even installed in your situation...may a code or inspection requirement because they are garden hose thread?
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wrote:

I've never been anywhere that required backflow preventers on a washing machine. The control valves on washing machines are right where the hoses hookup. And the fill to the tub is above it. You might be able to simply replace the rubber washer to fix your leak. The fittings are the same as garden hoses. Personally I'd probably remove the backflow preventers.
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On 07/12/11 07:31 am, jamesgangnc wrote:

I took apart the leaking one and found that the rubber/plastic "diaphragm"(?) was a sticky black mess, so fixing it would require getting the appropriate replacement part.
I cannot find such a device on Lowe's Web site, and Menards (regional home improvement chain) shows it a s a special-order item, so I conclude that they are not widely used. Home Depot sells them, but our local store closed recently.
Since HD describes the item as for a garden hose, it is presumably not intended for hot water.
I think I might just remove them.
Perce
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Yes, those are for outdoor use and when activated will release the excess pressure on the hose side to the ground. Probably not much water though.
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I agree that I've never seen them on a washing machine. They aren't on mine and I'll sleep soundly at night. It would be almost impossible for dirty washing machine water to make it back into the fresh water supply. For starters, the washing machine solenoid valves would have to fail to close at the same time the water pressure went to zero.
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On 7/12/2011 06:49, snipped-for-privacy@optonline.net wrote:

If the things are meant for garden hoses I wouldn't sleep soundly at night if they were on the washing machine lines because:
- They aren't intended for use under continuous pressure - They aren't intended for use with hot water - They're intended for outdoor use where water dripping from does no harm
Local codes may require them to be retrofitted on garden hose spigots prior to an inspection, such as when a property is sold. I suspect that the seller may have erroneously considered the washing machine taps to be garden hose taps.
--


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On 7/11/2011 10:54 PM, Percival P. Cassidy wrote:

http://www.homedepot.com/h_d1/N-5yc1v/R-202560207/h_d2/ProductDisplay?langId=-1&storeId051&catalogId053
Can't imagine why you would need it and have never seen them installed on a washer.
If you think about it every washer I know of already has a built in air gap because the water from the solenoid valves is routed to an outlet on the top of the machine that is above the highest water line.
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On 7/12/2011 9:26 AM, George wrote:

I also think washers have anti-siphon built in.
Could be the backflow preventers at the faucets are in case a hose is connected instead of the washer. Could be local practice. The OP could ask a plumbing inspector if they want a backflow preventer. I would leave it off, and install one if flagged at home sale.
When some plumbing work was done here, a backflow preventer was installed on the laundry tub faucet that is threaded for a hose. They were not installed on washer faucet connections.
--
bud--


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I wonder if what the OP has are not backflow preventers, but maybe those automatic valves that shut the water off if a hose breaks???
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If they are not exactly like the Home Depot unit, then they are probably some disaster mitigating device. The HD thing is for power washers, not laundry. Check with City Hall to see if they are some code required device, and if not, toss them. If there was a diaphragm internally, it might have been a pressure control or water hammer calming widget. If it turns out to have some merit, let us know.
Joe
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On 7/11/2011 9:54 PM, Percival P. Cassidy wrote:

http://www.homedepot.com/h_d1/N-5yc1v/R-202560207/h_d2/ProductDisplay?langId=-1&storeId051&catalogId053
no they don't need to be there. Design of the washer itself would prevent back flow in this imaginary scenario the water companies would have us to believe.
--
Steve Barker
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Percival P. Cassidy wrote:

http://www.homedepot.com/h_d1/N-5yc1v/R-202560207/h_d2/ProductDisplay?langId=-1&storeId051&catalogId053
Purpose: Water pressure drops. It drops so much, it's a suction! Double-nasty, dirty, bacteria laden, brackish water is sucked into the distribution line. Eventually the pressure is restored and you or your neighbor gets a glass of a less-than-tasty beverage that even a double-helping of sugar-free Kool-Aid powder can mask.
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On Tue, 12 Jul 2011 16:10:07 -0500, HeyBub wrote:

Only if the washing machine was operated in a grossly tilted position that would also flood the room.
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On 7/14/2011 11:04 PM, Michael Dobony wrote:

Not to mention, that scenario is sooooo far fetched, the cons of having all these anti-backflow devices far out weigh any benefit they could provide. IT's a joke. I'll not have them.
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Steve Barker
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Most responders in this thread are correct. Backflow preventers are not needed on a washer because there is already a siphon break component within the machine itselft. And in my experience as a major appliance repairman, it is very hard to make backflow preventers not leak, at the point they connect to your faucet, and at the point your hoses connect to them.
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Agaun, I wonder if what the OP has are not backflow preventers, but maybe those automatic valves that shut the water off if a hose breaks???
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