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Taco X-Block

Tom Hopkins
Tom Hopkins Member Posts: 552
I install quite a few of these.
Do you have it set up for
Outdoor Reset
Delta T control
Single Setpoint?

It matters in the programming.

I love the product by the way. I use it for all small HX jobs.


  • Taco X-Block

    We have one installed for a small radiant job in Berkeley working off a Noritz "on-demand" water heater. We started it us this week and the "heat source" pump does not come on on the X-Block; switched the controller to manual and the pump works. Seems I have a bad relay somewhere? Any ideas?
  • Weezbo
    Weezbo Member Posts: 6,232
    Could you have your outside sensor disconnected or..

    the relay to the on demand heater not sending information?

    the circ on the X block no mojo...well, test the operation right quick of the block . i think you can hold down the third button for like 10 seconds...the pumps cycle up then down the burner cycles up then down...you will have to read that part in the manual though ..its been nearly two years since i installed my first one...so the reading is not fresh on my mind...

    i thought the same thing as joe, maybe you dont have the design parameters set quite right therefore the pump doesnt go. the test button is the easiest way to determine that .
  • Joe Mattiello
    Joe Mattiello Member Posts: 705

    Apparently, you have something going on in the menu settings. You might have the boiler minimum enabled, and the X-pump block is trying to protect the boiler minimizing the amount of flow through the exchanger. Try turning the Boil Min set point to OFF. See if that makes a difference. The Manual switch simply validates the pumps run, so it has to be design set point problem. The distribution pump will run at full compliment even if the injection pump has ramped down. You can call me directly at 401-942-8000 X 484
    Joe Mattiello
    N. E. Regional Manger, Commercial Products
    Taco Comfort Solutions
  • DanHolohan
    DanHolohan Member, Moderator, Administrator Posts: 16,521
    I think it's great

    when a factory guy is so responsive. Thanks, Joe!
    Retired and loving it.
  • Wayco Wayne_2
    Wayco Wayne_2 Member Posts: 2,479
    WWI (Watching with intrest)

    I just got a Taco HX from the UPS guy today. Will install next week. It very well could be trying to protect the boiler from low boiler return temps. Please let us know what you find out. WW

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • gary bettcher
    gary bettcher Member Posts: 22

    could be the warm weather shut down is not set right.
  • Weezy,

    Joe and Gary...............thanks for your help and will check out the controller and parameters later this week. And yes, it's nice to have a responsive ear at Taco.

    All the best,

  • Tom Hopkins
    Tom Hopkins Member Posts: 552
    X Pump set up

    One more thing.

    The on board pump on the X is not powerful enough to move water through the Noritz.

    You usually need a beefy pump ie: Grundfoss 26-99 in a primary loop through the Noritz, then use the pump on the x as the secondary
  • Noritz

    Last time I checked, the Noritz has a less restrictive heat exchanger and you only need to pump 2 gpm at 10 ft. of head.
    At 10' of head, the Taco 008 in the X-Block will push 8 gpm. That's why I like the Noritz so much.

  • Thanks, Joe!

    I lowered the BOIL MIN to off and the pump started right up. Thanks so much for your help.

    The homeowners thank you as well. It's starting to get below 60° here and out here, that's freezing.

    All the best,

This discussion has been closed.