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boiler loop

buzzy
buzzy Member Posts: 8
in Radiant Heating
i,m installing a new low mass gas boiler into an existing system{old house},i recently learned that 2 close coupled t's should connect the existing system ,then my new boiler would connect to the t's,which requires the existing circ pump to run the existing system while the new pump {manufacturer recommended}would run only the boiler loop,is this right and should they be wired to run at the same time,boiler pump runs on call for heat,

Comments

  • CMadatMe
    CMadatMe Member Posts: 3,086
    Whose Boiler

    Whose boiler is it? I take it you are zoning with zone valves. In that case yes. The boiler pumps job is to move the water through the boiler the system pumps job is to move the water through the system. They both should run at the same time. What are you doing for domestic hot water?

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  • buzzy
    buzzy Member Posts: 8
    reply

    no zone valves,one thermostat in whole house,domestic water is seperate[elec]
  • CMadatMe
    CMadatMe Member Posts: 3,086
    Boiler?

    What make and model boiler? What is the heat loss of your home? What pump did you use for the boiler pump?

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  • buzzy
    buzzy Member Posts: 8
    reply

    weil-mclean cgi-4,not sure of the pump size,i,m at home now
  • CMadatMe
    CMadatMe Member Posts: 3,086
    ?

    Now I'm really confused. There is no need to primary/secondary this boiler. In case you lost the install manual it is attached. I would strongly suggest you get a pro in your area.

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  • buzzy
    buzzy Member Posts: 8
    reply

    i am a contractor,i recently attended a 2 day introduction to hydronic heating installation course,while looking back at the course manual it clearly states to do what i suggested,but it does not explain how the pumps should run,hydraulic independence
  • CMadatMe
    CMadatMe Member Posts: 3,086
    edited June 2010
    Not meant to Offend

    Sorry didn't realize you were a contactor The boiler you are installing does not need primary/secondary unless you are trying to protect the boiler from cold return water temps because your seconday loop is delivering lower than 140 degree return water temp. If your system is radiant, you are doing outdoor reset, injection pumping etc you may need it but other than that it is not necessary. Here are a few links that may help you understand the reason of why pri/sec is necessary.

    http://www.pmengineer.com/CDA/Archives/9c4975fa31298010VgnVCM100000f932a8c0____



    http://www.comfort-calc.net/primary-secondary_piping_tutorial.html



    If you want a really good book go to Dan's Shop and find Modern Hydronic Heating Second Edition. Best and only reference you may find you will ever need. The installation manual I attached in the previouse post gives you the recommended piping for different applications. You should always fall back to the manufacturers manual  when you are in question so that you do not void any warranty due to improper installation. Page 40 shows you how to wire. To answer your original question. Wire boiler circ as show and wire your zone therm to a single zone circ relay take the end switch from the relay to TT as shown. Boiler circ will run on a call for heat.

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