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making radiant more precise with condensing boiler.

charliej Member Posts: 1
I have a new boiler, Lochinvar, and the problem i have is with the radiant in the spring and fall when the outside temperature is fluctuating. The thermostat shows its calling for heat but, its not satisfied on days when there is a rise in outside temperature.I do have my hot water tank on a separate zone and no problems there, I want to know if there is a mechanical fix to augment the heat in radiant areas when thermostat is calling.
I should think there is but is there?


  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 7,574
    edited March 2021
    That should be in the heating program parameters of the Lochinvar control. I'm not familiar with your model but it seems like the boiler water temperature could be a bit higher at the low end. If you have enough heat at very cold times, then the high-temperature boiler water parameter is correct. You will need to read the setup portion of the manual to make that adjustment.


    If less than 1 year old, the installing contractor may be able to help at no charge. The setup is a trial and error situation with some of these boilers because every system is slightly different. Once you get it dialed in... You should be fine all year from season to season.

    Edward F Young. Retired HVAC ContractorSpecialized in Residential Oil Burner and Hydronics
  • hot_rod
    hot_rod Member Posts: 21,866
    If the outdoor reset function is being used, it may need to be dialed in better.
    The boiler should also have a function (boost) that ramps up supply temperature if a demand or load is not met in a certain time period. Maybe that is not activated?
    No reason the boiler should not cover the load under any condition.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • hcpatel78
    hcpatel78 Member Posts: 151
    edited March 2021
    I am facing exactly same here with noritz CB199. I have done setup in boost temp as @hot_rod mentioned.
    I setup such a way that when my heat call is not satisfied within 20 minutes then my set water temperature from ODR will increase 20F.
    So let's say in spring it runs at 100 SWT and my heat call is still there for more than 20 minutes then controll increases the SWT to120F, Untill it satisfies the heat call from thermostat. Once that cycle is finished the ODR take over as original setup.

    As @EdTheHeaterMan mentioned trial and error needed until you fine tune that.

    Thank you,
    Hiren Patel
    JUGHNE Member Posts: 11,021
    My Lochinvar KBN has Warm Weather Shut Down (WWSD). So it is adjustable on the control panel.
    Mine is set too high to keep the bath at 74 on a moderate day. The zone/pump keeps calling and pumping cool water.