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Grundfos Magna - which mode?

Matt_67 Member Posts: 193
I just installed a grundfos magna on a cast iron radiator system with TRV's and outdoor reset.  I am just curious what mode others have used in in this situation and with what results.  The other times I've used the magna were on apartment buildings with zone valves - I left it in the auto-adapt mode and it worked fine.


  • CMadatMe
    CMadatMe Member Posts: 3,066

    Model? The modes are clearly spelled out in the manual dependent on system type and head requirements. For instance a 65-120 would be run in the proportional mode if the head is higher then 13'..
    "The bitter taste of a poor installation remains much longer than the sweet taste of the lowest price."
  • Matt_67
    Matt_67 Member Posts: 193
    grundfos 40-120

    It is a 40-120.  The system has some long marginally sized pipe runs to the furthest radiators.  I left the pump in the proportional pressure mode as per the manual.  I guess I'm just trying to understand why that would be better in my situation.  Constant pressure makes more sense to me.
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