How do mod-con boilers modulate?

Discussion in 'Boiler Forum' started by Kim Park, Apr 3, 2021.

  1. Kim Park

    Kim Park New Member

    Joined:
    Apr 3, 2021
    Location:
    Glen Cove
    Hi,

    I currently have a Bosch gb142 /30 (input 106,000, turn down ratio 5:1), which was installed in 2009. Its combustion chamber started a leak and was replaced under warranty in 2019. A lot of other parts also have been replaced. Right now only the control panel and the fan are original. I don't know how long it would hold up. I am pretty sure that it is way oversized and would like to replace it with a smaller boiler (a higher turn down ratio) when the time comes.

    lochinvar WHB085N (turn down 10:1) and htp EFTU-85WBN seem to be best candidates. When I am reading the lochinvar sale brochure, it states "ECM pump technology saves electricity & lowers operating costs. Lochinvar now includes this money saving technology as standard equipment on all WHB & KHB boilers. Using the Smart System to continuously match the target Delta T at all modulation rates this technology makes variable speed pump integration simple and easy." I am confused because my understanding is that the mod-con boilers modulate based on the return water temperature. If a mod-con boiler is installed with a Delta t ecm circulator, then the return water temperature is constant, the boiler would not modulate, right? Am I missing something?

    Thanks!
     
  2. fitter30

    fitter30 Well-Known Member

    Joined:
    Feb 2, 2020
    Occupation:
    Retired service tech
    Location:
    Peace valley missouri
    Modulation of the boiler looks at incoming and out going water temp varying vent motor/ blower rpm and gas pressure to maintain correct burner function o2 and co. ECM stands for an “electronically commutated motor they are electronic controled. They can vary rpm or not and are very energy efficient . For the difference in price there well worth upgrating.
    https://www.tacocomfort.com/product/007e-ecm-high-efficiency-circulator/
     
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  4. Kim Park

    Kim Park New Member

    Joined:
    Apr 3, 2021
    Location:
    Glen Cove
    My question is: can a delta t ecm circulator be installed with a mod-con boiler and won't affect its modulation?
     
  5. fitter30

    fitter30 Well-Known Member

    Joined:
    Feb 2, 2020
    Occupation:
    Retired service tech
    Location:
    Peace valley missouri
    Using a lockivar boiler with factory emc pump with boiler talking to burner and pump have no problems with that but if you have multi zones. Zone pumps varying flows might not heat all heat emitters properly or ramp up and down to fast. Emc pump like a e007 is going to save. Start adding different systems each one will bring on different problems unless you have the skills to program and time to play wth designing a control system.
     
  6. Kim Park

    Kim Park New Member

    Joined:
    Apr 3, 2021
    Location:
    Glen Cove
    Thanks!
     
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