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Navien CH-240 and additional pump

attn Member Posts: 2
Anyone have experience installing <strong>CH-240</strong> in simple 2 store building. Is additional pump required for such simple installation i.e single thermostat with no multiple zones ? I've just confused little bit that some contractor saying that additional water pump required even unit itself already have build-in water circulation pump.  Manual not clear about this too. It doesn't indicate that pump is required for primary heating loop and only for secondary and other loops. What if I only have a primary heating loop ?


  • RobbieDo
    RobbieDo Member Posts: 131

    Do you have pics of how this is piped?? It sounds like you don't have primary/secondary piped in properly. Thanks
  • Gordan
    Gordan Member Posts: 891
    edited March 2011
    Depends on the pressure drop and flow requirements

    The built-in pump may not (and probably does not) be sufficient to maintain the required flow against your system pressure drop. Hence the recommendation (requirement?) to pipe the appliance primary-secondary, and decouple the system flow from the appliance flow.
  • attn
    attn Member Posts: 2
    Navien CH-240 and additional pump

    Thank you. I understand I need extra pump. Which one would be good for 2 floors building + basement. Is 3 speed grundfos 15-58 is a good choice ?
  • Ironman
    Ironman Member Posts: 7,182
    More Info is Needed

    In closed loop, the bldg. height does not determine the size of the circulator.

    You will need to know your heat loss, gpm required, head loss, type of emitters, etc.

    See the attached thread:

    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • CMadatMe
    CMadatMe Member Posts: 3,086

    Why are you installing a water heater as a primary heat source? To anwser your question you do need to pri/sec so yes you need an additional system side pump. How did you wire in your low water cut-off and additional high limit aquastat with manual reset? This is commercial and that would be a requirement here. 
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
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