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Taco 5000 mixing valve adjustment--should it be 'exercised' to free debris etc?

D107D107 Posts: 1,534Member
In the ten years since the family house had the indirect installed, I've had to slightly adjust the Taco 5000 mixing valve once or twice. At this point it is reported that the water has gradually turned lukewarm in the shower. Troubleshooting by phone via Logamatic readings indicates the boiler is heating the hot water, and the water leading to the mixing valve is hot but coming out is not. So of course we'll turn the control counterclockwise to raise the water temp. If that doesn't work then we'll know the valve is shot or possibly filled with debris, even though our water out there is pretty clean and free of minerals. Should the control be 'exercised' back and forth like shutoff valves on circulators are? Or just turn counterclockwise until the desired temp is reached?


  • kcoppkcopp Posts: 3,325Member
    yes. I do this every once and in a while w/ mine.
  • D107D107 Posts: 1,534Member
    edited February 2017
    Thanks, and how far left and right of the current position do you move it? I would tend to think an inch or so either way would be enough.
  • D107D107 Posts: 1,534Member
    edited February 2017
    Sometimes the facts about the problem don't get reported to me fully or I didn't ask all the right questions. I now hear that all the other faucets have hot water, so that points not to the mixing valve but the shower body, which I believe is the Moentrol 3170 which is a pressure balanced valve. Installed about 9 years ago.
  • kcoppkcopp Posts: 3,325Member
    You can get a replacement cartridge and replace that relatively easy.
  • sgust91250sgust91250 Posts: 1Member
    Can this valve cause water to pulse? All my hot water faucets are cycling every few seconds between almost normal pressure and about half pressure. Cold side is fine and pressure tank is normal. Not sure how a limed up valve could cause this but maybe. Or other causes? Not really sure it’s the valve but don’t know what else it could be. Thanks for any thoughts.
  • hot_rodhot_rod Posts: 11,629Member
    Sometimes there are small screens installed in the H&C ports of those mixing valves, could be one, or both are partially plugged if it is a flow issue.

    If it is a thready temperature, usually that indicates a cartridge inside getting scaled up and not moving freely.

    Clean and rebuild or replace it.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
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