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Re-Piping Primary/Secondary - Which Approach?

JustinS
JustinS Member Posts: 259
edited December 2014 in THE MAIN WALL
The HVAC company I've chosen to fix my piping initially proposed something like this (see pic #1 - in case it's not clear, this is the one with the orange loop btw CH supply and return ports under boiler)

My initial reaction was that it didn't match any of the examples in the manual since the boiler was on a loop with the supply and return headers Td off it... So they suggested an alternative like #2 that more closely matched the manual...

Any preferences?

****EDIT****

Sorry, should have included some background - my Triangle Tube Prestige Solo 110 is short-cycling because the CH Supply (front right) and DHW Supply (back right) are tied together in a loop... I've been told to have it re-piped primary/secondary so that brings us to now...

What I'm wondering is if it's a valid P/S scheme where the boiler ties CH Supply and Return in a primary loop with closely-spaced Ts leading to the Supply and Return headers... I ask because the TT install manual only shows the boiler as the thing on the closely-spaced Ts off a primary loop that consists of CH Supply and Return... the installer says they're the same... just want to confirm and see if folks here have a preference...

Comments

  • Ironman
    Ironman Member Posts: 7,611
    edited December 2014
    Your first drawing shows p/s. Your second is direct return, not p/s.
    What make of boiler is that? Does it have an internal circulator? If not, then you'll need one in the boiler loop.
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • JustinS
    JustinS Member Posts: 259
    edited December 2014
    The 2nd picture, I was attempting to show that there were Ts after the loop back... I guess it looks like there's no connection btw the piping to the two ports.

    Please see new image, is that any better?

    And the boiler is a TT Prestige Solo 110 and yes it does have an internal circulator...
  • Ironman
    Ironman Member Posts: 7,611
    What's the third connection at the boiler? Is this a Triangle Tube?
    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • JustinS
    JustinS Member Posts: 259
    Yes, it's a Triangle Tube... Back right is DHW supply, front right is CH supply and back left is common return... My DHW joins with CH return upstream of the return shown here...
  • Zman
    Zman Member Posts: 7,611
    Both configurations will work just fine.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • JustinS
    JustinS Member Posts: 259
    Zman said:

    Both configurations will work just fine.

    Thank you Carl
  • hot_rod
    hot_rod Member Posts: 23,771
    also consider a hydro separator. This give you four functions in one. Air, dirt and magnetic separation and P/S.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • BigRob
    BigRob Member Posts: 324
    hot rod said:

    also consider a hydro separator. This give you four functions in one. Air, dirt and magnetic separation and P/S.

    Rod is right. I had a bad situation where a buddy and I had to blow out a gallon bucked of iron oxide particles. The system was a big one and had been neglected. A small leak provided an oxygen entry path. It was not fun and the air separation is very good insurance if you don't already have it.
  • JustinS
    JustinS Member Posts: 259
    Thankfully, I believe that I already have an air separator right above the expansion tank
  • JustinS
    JustinS Member Posts: 259

    BigRob
  • JustinS
    JustinS Member Posts: 259
    When I'm having this re-piped, should I see about installing flow check valves on the return lines, most specifically on the dedicated return from the DHW tank?

    All of my circulators are IFC models so it looks like my CH ones match the TT piping examples; however, the examples show the DHW circulators without an IFC and with a flow check valve on the return piping...

    As I understand it, both a circulator with an IFC and a flow check valve on the return will prevent backwards flow into the circuit, right? But should I still have a flow check valve on the return to prevent heat migration or is the fact that I have a heat trap on the DHW return sufficient to prevent it?

    Please see my attached piping... thank you again...
  • Paul48
    Paul48 Member Posts: 4,469
    Justin....It couldn't be any simpler. Re-pipe it exactly as depicted in the I&O manual (no more, no less).
  • jonny88
    jonny88 Member Posts: 1,139
    Hot Rod I have a install coming up on 2 weeks where customer (who also designs my heating systems) is using your hydro seperator.I cant wait it will be my first time to use this,he is a real Caleffi stickler everything Caleffi which he introduced me to.Now my supply house stocks your fill valves ,dirtmags etc.Looking forward to the seperator though.
  • JustinS
    JustinS Member Posts: 259
    Paul48 said:

    Justin....It couldn't be any simpler. Re-pipe it exactly as depicted in the I&O manual (no more, no less).

    Well, both the new installer and the TT rep said the DHW return piping is fine as it is... and neither thinks that the check valve is necessary...
  • Gordy
    Gordy Member Posts: 9,546
    It's fine pipe it. Get on with it.
    Canucker

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