# dualing symmons mixing valves



## Plumb26 (May 18, 2013)

Customer has high/low setup with separate valves. (not the all-in-one kind). Can not keep consistent temperature fluctuates from 90*-125*. I shut one down and adjusted temps and they held. Shut it down and adjusted the other to same temp. It held. When I turn them both on, it goes all over the place but, not fast enough to notice right away. Both have been rebuilt recently and took both apart and they aren't scaled up or anything. Any help would be appreciated.


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## Redwood (Sep 8, 2008)

Plumb26 said:


> Customer has high/low setup with separate valves. (not the all-in-one kind). Can not keep consistent temperature fluctuates from 90*-125*. I shut one down and adjusted temps and they held. Shut it down and adjusted the other to same temp. It held. When I turn them both on, it goes all over the place but, not fast enough to notice right away. Both have been rebuilt recently and took both apart and they aren't scaled up or anything. Any help would be appreciated.


I'd suspect a hot water supply issue aggravated by higher flow conditions.
Are the pipes sized adequately?
Is there a tempering valve in use?
How is the hot water made? Tank, boiler coil, tankless???
Is the temperature consistent at the outlet of the water heating device when both are in use?
If a tempering valve is in use is the temperature at the outlet consistent when both mixers are in use?

That should give you some direction...


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## SewerRatz (Apr 25, 2009)

Also check the flow o the recirculation system, along with where it is tied in.


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## Redwood (Sep 8, 2008)

On The Symmons valves the pressure balancing spool is inside of the TA-10 Spindle and is easily checked by shaking it front to back.
You'll hear it clacking back and forth...
I didn't say that before because I really don't think it is the problem they are pretty reliable and usually stick to full hot or full cold only after a long period of no use.

I don't believe you have a crossover problem because that would most likely affect even the operation of a single valve.


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## Tommy plumber (Feb 19, 2010)

SewerRatz said:


> Also check the flow o the recirculation system, along with where it is tied in.














Maybe a bad check valve on the hot re-circ.


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## gplumb (Nov 21, 2008)

So plumb26, what's the outcome. These have been a pain for me too.


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