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re-piped old Radiator with 1/2" AL-PEX not enough flow need to replace with 3/4". HELP

DennisBrownNYC
DennisBrownNYC Member Posts: 26
in Radiant Heating
Replaced My old GAS boiler system from black iron 1/2'' pipes with 1/2'' Viega FostaPEX PEX-AL-PEX and Viega 10 - Loop ProRadiant Stainless Steel Manifold. Cast Iron radiator isn't as hot as it use to be. Some parts are hot and other parts are lukewarm. Hvac guys From my job suggest replacing with 3/4"AL-PEX. Also, before I transitioned to Al Pex My System would make a loud Noise, It is still present.

Pictures

Shopping Cart.

3/4" FostaPEX PEX-AL-PEX Tubing (150 ft. coil)

3/4" PEX Press x 1/2" Male Adapter w/ Sleeve (Lead Free)

3/4" PEX Press x 1/2" Female Adapter w/ Sleeve (Lead Free)

3/4" PEX Press Coupling w/ Sleeve (Lead Free)

1/2" PEX Press 90° Elbow w/ Attached Sleeve (Zero Lead Bronze)

3/4" PEX Press 90° Elbow w/ Attached Sleeve (Zero Lead Bronze)

3/4" PEX Press x 1/2" Female Adapter w/ Sleeve (Lead Free)

ProRadiant 3/4" SVC Compression PEX Adapter, 2-Pack


It would be great for any suggestion about adding to my system, Thanks

Comments

  • mattmia2
    mattmia2 Member Posts: 10,919
    What kid of boiler is it? What does te near boiler piing look like? Is this radiator connected directly to the manifold and is the manifold piped directly to the boiler or is it sharing this pipe with multiple emitters? You can move quite a bit of heat through a 1/2" pipe.
    DennisBrownNYCLS123
  • kcopp
    kcopp Member Posts: 4,472
    Are you still warm? What type of boiler as asked above? It may be the manifold they can be pretty restrictive...
    DennisBrownNYC
  • DennisBrownNYC
    DennisBrownNYC Member Posts: 26
    edited February 2021
    mattmia2 said:

    What kid of boiler is it? What does te near boiler piing look like? Is this radiator connected directly to the manifold and is the manifold piped directly to the boiler or is it sharing this pipe with multiple emitters? You can move quite a bit of heat through a 1/2" pipe.

    kcopp said:

    Are you still warm? What type of boiler as asked above? It may be the manifold they can be pretty restrictive...

    Cast iron New yorker Boiler CG50DNI-G2 94,000 BTU
    4.8 gallons Calefactio HGT-30 Expansion tank
    Armstrong S-25 BF Cast Iron In-Line Pump, 1/12 hp
    Supply Lines 1 1/4 copper pipes

    Radiator is Connected Directly to the Manifold, Like this

    All the radiators are ran off their own own loop. 9 radiators 9 loops for each individual one.

    Sorry for the late response. Busy with work.

  • Ironman
    Ironman Member Posts: 7,547
    Are the flow setters open all the way at the manifold?

    Are all of your radiators now connected to the manifold?

    How about posting some pics of the manifold, the boiler and its near piping?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • DennisBrownNYC
    DennisBrownNYC Member Posts: 26
    edited February 2021
    Ironman said:

    Are the flow setters open all the way at the manifold?

    Are all of your radiators now connected to the manifold?

    How about posting some pics of the manifold, the boiler and its near piping?

    these are the Pics
    https://imgur.com/a/z76g1HG
  • Ironman
    Ironman Member Posts: 7,547
    You've increased the head in the system going with long runs of 1/2" tubing where there were previously short runs of 3/4" iron pipe. That Armstrong s-25 is a low head, high volume pump that's not designed for the higher head. You need to use a Grundfos ups15-58 or equivalent.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    DennisBrownNYC
  • DennisBrownNYC
    DennisBrownNYC Member Posts: 26
    Ironman said:

    You've increased the head in the system going with long runs of 1/2" tubing where there were previously short runs of 3/4" iron pipe. That Armstrong s-25 is a low head, high volume pump that's not designed for the higher head. You need to use a Grundfos ups15-58 or equivalent.

    So replace 1/2 with 3/4 and replace pump.

    Any additional suggestions?

    Because i want to put in the order today so i can have the heat running the remaining of the winter to make sure its working correct.

    Thank you.
  • DennisBrownNYC
    DennisBrownNYC Member Posts: 26
    I really appreciate all of the information i'm getting.
  • DennisBrownNYC
    DennisBrownNYC Member Posts: 26
    @Ironman I looking at UPS26-99FC, 3-Speed Circulator Pump, 1/6 HP, 230 volt or UPS26-99FC, 3-Speed Circulator Pump, 1/6 HP, 230 volt. or would the Grundfos ups15-58 be efficient.
  • Ironman
    Ironman Member Posts: 7,547
    The 26-99 would be too large. Use the 15-58. I've got radiant floors with 14 loops of 1/2" PEX at 250' each and a 15-58 on medium speed doing it all just fine.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    DennisBrownNYC
  • DennisBrownNYC
    DennisBrownNYC Member Posts: 26
    Ironman said:

    The 26-99 would be too large. Use the 15-58. I've got radiant floors with 14 loops of 1/2" PEX at 250' each and a 15-58 on medium speed doing it all just fine.

    Got it. so i can keep the 1/2'' or replace with 3/4''?

    Thanks
  • Ironman
    Ironman Member Posts: 7,547
    The 1/2" should be fine with a new circulator.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
    DennisBrownNYC
  • Robert_25
    Robert_25 Member Posts: 549
    Wrong circulator.

    Is your pex laying on the flue pipe of the boiler?
    DennisBrownNYC
  • kcopp
    kcopp Member Posts: 4,472
    I still think that manifold is part of the issue. I had problems w/ that style manifold in the past.
  • DennisBrownNYC
    DennisBrownNYC Member Posts: 26
    Robert_25 said:

    Wrong circulator.

    Is your pex laying on the flue pipe of the boiler?

    Flue Pipe? I don't know what that means
  • DennisBrownNYC
    DennisBrownNYC Member Posts: 26
    Ironman said:

    The 1/2" should be fine with a new circulator.

    Thanks
  • DennisBrownNYC
    DennisBrownNYC Member Posts: 26
    kcopp said:

    I still think that manifold is part of the issue. I had problems w/ that style manifold in the past.

    How did you fix your situation? did you replace the manifold?
  • mattmia2
    mattmia2 Member Posts: 10,919
    edited February 2021
    DennisBrownNYC said:

    Robert_25 said:

    Wrong circulator.

    Is your pex laying on the flue pipe of the boiler?

    Flue Pipe? I don't know what that means
    Where it passes above the boiler, it is on(or too close to) the vent that goes in to the chimney. The pex needs a lot more support in general, but make sure it can still expand and contract in length.
    DennisBrownNYC
  • DennisBrownNYC
    DennisBrownNYC Member Posts: 26
    mattmia2 said:

    DennisBrownNYC said:

    Robert_25 said:

    Wrong circulator.

    Is your pex laying on the flue pipe of the boiler?

    Flue Pipe? I don't know what that means
    Where it passes above the boiler, it is on(or too close to) the vent that goes in to the chimney. The pex needs a lot more support in general, but make sure it can still expand and contract in length.
    Got it. I will A hanger to that area. To strap it.
  • DennisBrownNYC
    DennisBrownNYC Member Posts: 26
    DennisBrownNYC said:

    kcopp said:

    I still think that manifold is part of the issue. I had problems w/ that style manifold in the past.

    How did you fix your situation? did you replace the manifold?
    @kcopp
  • kcopp
    kcopp Member Posts: 4,472
    DennisBrownNYC said:

    kcopp said:

    I still think that manifold is part of the issue. I had problems w/ that style manifold in the past.

    How did you fix your situation? did you replace the manifold?
    Yes.
    I went w/ a very low pressure drop Sioux chief manifold. No flow meters...just ball valves. Made all the difference.
  • DennisBrownNYC
    DennisBrownNYC Member Posts: 26
    kcopp said:

    DennisBrownNYC said:

    kcopp said:

    I still think that manifold is part of the issue. I had problems w/ that style manifold in the past.

    How did you fix your situation? did you replace the manifold?
    Yes.
    I went w/ a very low pressure drop Sioux chief manifold. No flow meters...just ball valves. Made all the difference.
    Thanks

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