Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Weil Mclain ECO 155 gas piping design question

Izzydaangler
Izzydaangler Member Posts: 3
Hello,

I am a plumber from the philadelphia area. I have never installed one of these units before. I am installing one in my home and I want to get it right.

I have three heating zones and three circulators.

My old boiler was piped with an 1.5 supply header to 3 loops. Each 3/4 copper to fin tube.

The returns all returned to there own circulator into a 1.5 return header.

Can this eco be piped in the same fashion and is there controls available to handle 3 thermostats and 3 circulators?



Maybe if someone has experience with this situation they could diagram a design for me that works as per manufacturers recommendation. I cannot find anything like it in the manual.

Thank you

Comments

  • Zman
    Zman Member Posts: 7,561
    Sizing

    How did you arrive at 155? How many LF of baseboard do you have? Have you done a heat loss?



    The manual on that one is a math contradiction. You cannot have a max flowrate of 14.5 gpm and a min.delta t of 20  it just is not possible.



    First determine the heating requirements, then work through the MW manual?
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Izzydaangler
    Izzydaangler Member Posts: 3
    piping design

    Hello

    Its not a question of sizing. I have an established heating system in this old victorian. It was an old oil fired boiler with 3 zones.

    The heater was sized correctly. I need advise from someone who has installed this heater or one like it and how they piped the three zones in using 3 circs and 3 thermostats.

    Thanks
  • SWEI
    SWEI Member Posts: 7,356
    It's ALWAYS a question of sizing

    Approximately what size is the house, and where is it located?
  • Zman
    Zman Member Posts: 7,561
    Sizing

    Of course it is about sizing.

    An incorrectly sized boiler will short cycle and have reduced service life and efficiency.

    You can not do a piping design without accurate flowrates and you cannot figure flowrates without sizing.

    The new boiler is more efficient than the old so should be smaller. The home has likely had insulation upgrades so the requirements would have changed. Who is to say the previous installer put in the right size?

    If you are going with the "bury your head" in the sand approach, put in the 155 and pipe it primary/secondary per the manual and walk away.

    If you want a properly sized and designed system, do a heat loss calc.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Rich_49
    Rich_49 Member Posts: 2,766
    How

    do you know it was properly sized before ?  Old Victorian and properly sized have never appeared in the same sentence in my career . Do the heat loss , measure the installed radiation and at least see if you can lower the water temps and use the ODR . I'd be willing to wager that the boiler is at least 2xs oversized , don't forget the buffer tank my friend . Have fun with the 88% efficiency and by the way , cycling is not good unless your in the Tour de France .
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    732-751-1560
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • icesailor
    icesailor Member Posts: 7,265
    Heat Loss Calculations:

    If you're not doing a complete and accurate heat loss calculation, you might as well just stick the biggest CGI, draft hood boiler you can afford and forget about efficiency. Doo it quickly before the energy/EPA codes change for 2015.

    Oversized high efficiency boilers are a waste of the initial money and a waste of operational money. And if you don't read the I/O manual and install it just like shown, you might throw more money away on a quicker boiler failure that isn't covered under warranty.

    You wouldn't want a 600 HP engine in your commuter small car. It would be un-drivable.
  • Boiler wrestler
    Boiler wrestler Member Posts: 43
    eco

    This boiler cannot control all your circulators, you will need to get a WMCR 3 circulator zone controller or similar.



    As for piping,you will need to look on page 48 figure 51.



    As others have said, check your sizing first.
  • Izzydaangler
    Izzydaangler Member Posts: 3
    sizing

    Ok I think I understand. Shall I measure all of the baseboard for a total? What else is needed to size?
  • Rich_49
    Rich_49 Member Posts: 2,766
    The Neighborhood

    is where you need to visit . Taco FloPro University is an online tool free for anyone who wants to learn . Take a look and it will tell you everything you require for a heat loss . Welcome to the world of doing it right .



    http://flopro.taco-hvac.com/flopro_u.html
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    732-751-1560
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • Zman
    Zman Member Posts: 7,561
    Heat loss

    The baseboard length will tell you the largest boiler you could possibly need.

    The heat loss will tell you exactly what size you need.

    With both pieces of info, you will know what your design water temp needs to be in order to maximize the efficiency of the new condensing boiler.

    Cool stuff...
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
  • Paul48
    Paul48 Member Posts: 4,469
    Science

    It has come so far since the old days of " sticking a big boiler in a house". Doing it wrong, you might as well stand next to the boiler and burn dollar bills, one after another. There's plenty of time to do it the right way.