# drain tempering valve



## PLUMBER_BILL (Oct 23, 2009)

In this months P&M there was an ad for a drain tempering valve on page 8.
I clicked on their web site and I looked at their movie. No where that I can find, is a mention of "Backflow" -- but they do talk of cold water input into their valve which is inserted into drainage. 

Can anybody add to this post ... IMHO I think it would need protection to get code approval.

Comments !
http://www.thermomegatech.com/product-categories/drain-tempering/


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## Tommy plumber (Feb 19, 2010)

Excellent observation Bill. If for some reason, their valve sticks open and simultaneously there is no cold water during a negative pressure situation, then there would definitely be a cross connection of dirty dish rinse water contaminating the potable water line.

I notice that they didn't mention any ASSE {American Society of Sanitary Engineering} listing or any other listing agencies.


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## plumber11928 (Feb 18, 2015)

Yes good call Bill. It's a good idea. Maybe they figured a backflow would be our problem. A watts 9d behind it would be nice.


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## Greenguy (Jan 22, 2011)

I'm guessing you didn't check the install manual: first page bullet #5

http://www.thermomegatech.com/wp-content/uploads/2015/02/DTV_IMI.pdf

5) In most cases, a check valve is recommended on the cold water inlet to the DTV valve. Check local plumbing codes as to the type of check valve or backflow preventer that may be required.


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