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Capping Monoflo tee's

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Garoman
Garoman Member Posts: 4
I've an old house (75yrs) I'm working on with an old one inch c x c monoflo system with half inch tee's, one monoflo one regular. Additions to the house through the years have added separate zones for a kitchen addition, a family room addition and an enlarged 2nd fl bathroom. The existing 1st floor living Rm, dining room and three (3) 2nd floor bedrooms run off the monoflo system. All are done with old school baseboard heat emitters. I want to divorce the monoflo tees from the 1st fl living and dining room and then add those sections of baseboard to the family room zone leaving only the three bedrooms on the second floor running off the original monoflo system. I'll need to run a new Tstat to the second floor as the the one on the first floor controls up and down at this time. My instincts/experience/knowledge tells me that I must loop the monoflo tee's to the regular tee's so as not to create a PSI issue within the one inch main would "The Wall" agree?
In addition is there any potential problems with the old monoflo system being utilized just for the three (3) 2nd floor bedrooms as a separate zone?
Thank you in advance for your knowledge

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,631
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    What you are doing is exactly right. Connect the Monoflo tees with 1/2" copper. Monoflo tees are restrictive. If the branches are cut and capped, you will add to the total restriction of the Monoflo loop and could have flow issues
    kcopp
  • Garoman
    Garoman Member Posts: 4
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    Thanks Ed. Do you see any problem with just using the existing monoflo system as a seperate zone for the three bedrooms upstairs and nothing else?
  • mattmia2
    mattmia2 Member Posts: 9,749
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    The only issue you could have is with the boiler short cycling because the boiler doesn't have much load on it if only one zone is calling.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,631
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    Agree with @mattmia2
  • Garoman
    Garoman Member Posts: 4
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    Thank you Matt, thank you Ed. Wouldn't that be true of any multi zone boiler then>
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,117
    edited January 2023
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    Garoman said:

    Thank you Matt, thank you Ed. Wouldn't that be true of any multi zone boiler then>

    Yes. That is always the problem with standard boilers and multiple zoning. They usually work fine in most cases if the zones are all set at about the same temperature or at least most of the zones. The problem is when you have the smallest zone as the only zone used in the building and all the others are off or set very low.

    Micro-zoning has only become effective since the introduction of modulating boilers. Your system sounds like a standard ON/OFF that will cycle on the High Limit. Just as long as there are other zones that will operate at normal temperatures you should be fine. If you find that the short cycling from the high limit become a problem, then there are options like a buffer tank and outdoor reset available.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    mattmia2