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New Zone for Hot Water Heating

I have a two zone hot water heating system with a circulator pump on each zone.  I added a new branch (for a new radiator) to Zone 2 with a tee on the radiator side of the circulator pump.  But the hot water won't flow into the new branch on its own (path of higher resistance?).  It works fine when I isolate/shut Zone 1, but not when both Zones are running.

I don't want to re-pipe the system to make the new branch its own zone with a another pump on the boiler side of the current circulator ( if i don't have to). Can I add a circulator pump just for the branch? How would I wire that in so it worked in conjunction with the main pump in the zone?  Other ideas?
Mad Dog_2

Comments

  • Hot_water_fan
    Hot_water_fan Member Posts: 2,061
    I have a two zone hot water heating system with a circulator pump on each zone. I added a new branch (for a new radiator) to Zone 2 with a tee on the radiator side of the circulator pump. But the hot water won't flow into the new branch on its own (path of higher resistance?). It works fine when I isolate/shut Zone 1, but not when both Zones are running.


    How do you know there's no flow?
    Mad Dog_2
  • hot_rod
    hot_rod Member Posts: 23,560
    Got a drawing and some pics of how you connected it?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 9,552

    I have a two zone hot water heating system with a circulator pump on each zone.  I added a new branch (for a new radiator) to Zone 2 with a tee on the radiator side of the circulator pump.  But the hot water won't flow into the new branch on its own (path of higher resistance?).  It works fine when I isolate/shut Zone 1, but not when both Zones are running.

    Based on the description above This is the drawing I come up with. There is something missing.
    Can you make a drawing on paper and take a picture of it with your phone and let us see what you are talking about?

    OR

    Tale a picture of the Tee fitting you connected the new radiator from far enough back to see where the pipes are going. Boiler picture from floor to ceiling so we can see all the near boiler piping including the TEE you are talking about.

    Edward Young Retired

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

    Mad Dog_2
  • Mad Dog_2
    Mad Dog_2 Member Posts: 7,555
    Nice graphics man....Mad Dog  
  • doityourself
    doityourself Member Posts: 3
    Your drawing is pretty accurate.  Here is a picture.  The pipe gets hot right after the tee, but 20 feet away the pipe is pretty cool and the radiator is cold.  But there's water in the radiator.  When I close the valve to the rest of the house, the new branch heats up just fine.
  • Shane_2
    Shane_2 Member Posts: 194
    How does the cold water get back from the new branch?
  • doityourself
    doityourself Member Posts: 3
    It comes back into the return line for zone 1.  Hard to see that in the picture.