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.

primary secondary piping

smoore Member Posts: 28
If you were doing a residential boiler replacement with the whole house as one zone and say a high eff. condensing boiler like the weil mclain ultra why would you use prim/sec. piping? Why not resize the pump for head loss in the system and boiler at the needed flow? This would assure the right flow thru the boiler and with these high eff. boilers the colder the retutn water the higher the eff. so that shouldnt be a problem. thanks for any input.


  • Floyd_5
    Floyd_5 Member Posts: 418

    It can be done... I have one pump for my heat in my house...
    HOWEVER!!!!!!! be very carefull!!!!! My system is one zone, cast iron baeboard and cast iron rads....all running off of a 1-1/4" main with monoflo fittings to feed the baseboard and rads.....the head loss through my system is MUCH less than most systems...with the 0011 pump it works just fine.

    Now if I could just get the Ultra not to hit max. temp. @ 32 and reset on down further........it's coming.....so's Christmas!

    Merry Christmas Everyone!!!!

  • F Reynolds
    F Reynolds Member Posts: 92
    Have any ideas?

    You have just about the same exact system I have in my house, except, I do not have cast iron rads, I have cast iron baseboards, and my mains are a little larger at 1 3/4 inches. It was originally a gravity system. It appears, that my system, with constant circulation running, almost always overruns my thermostat by about 2 degrees on a large run from 66 to 70 degrees when I set it back during the day while I'm out. I'm wondering if I need to turn down my Outdoor Target Temp from 190 (factory setting) to say, 160. Do you think that would help reduce the overrun? Reynz
  • Earthfire
    Earthfire Member Posts: 543

    Stop playing the set back dance . The curcuit board can't learn you system requirements. Did you ever run a heatload and determine the btu required at design and the max temp required to deliver them at design. that is the only way to determine max temp settings. What is your wall termostat. if its a T87, you may need to adjust your antisipator.
  • F Reynolds
    F Reynolds Member Posts: 92
    Now, Now Earthfire

    "Stop playing the set back dance", Is that Hip Hop, Rap, Jazz or Country. Sounding a little hostile there Earthfire.

    "What is your wall thermostat? if its a T87, you may need to adjust your anticipator." My thermostat is a Honeywell 3600. Does it even have an anticipator? If so, how do you adjust it?

    I'm a little slow at this, that is the reason I ask all these questions. Be patient. I'm just relying on the obvious expertise of all who post and reply on this board to make sure my system is working as best as it can for warmth and economy. Reynz

  • F Reynolds
    F Reynolds Member Posts: 92

    Sorry, didn't answer the other question. No I did not do a heatload and I'm not sure what that is. Can you provide some more information?
  • F Reynolds
    F Reynolds Member Posts: 92
    Max Temp

    Floyd, Why don't you adjust the outdoor reset target tempature at 32 degree outside tempature to 160 or lower, rather than have it at 190? I assume you do know that can be done. I probably have misunderstood your statement.
This discussion has been closed.