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geothermal flow center

Having trouble with B & D 4 Circuit commercial flow center. All dual grundfos up26-99 pump circuits are overheating. By overheating I mean, the pumps are running hot, instead of cool 40 degrees like the source fluid temp is. I have used a flow meter tool to confirm 18 gpms through my heat pumps and ground loop. These pumps are eventually overheating and causing low pressure lockout on the geo units. The loopfield seems to be free of air, but I have not explanation why my pumps are running hot? This is a 24 ton geo RFH system in DM Iowa. 2) Hydron 12 tonners with dual 6 ton compressors 


  • Mark Eatherton
    Mark Eatherton Member Posts: 5,853
    Check voltage rating...

    I have seen some of these pumps mis-wired and they still run.

    Check the rating plate on the pump for required voltage, then check the supplied voltage.

    These wet rotored, water cooled pumps have been in use a LONG time, and if there were a problem, we'd have known about them long before now.

    Worst case, contact Grundfos USA and get a rep out to look the job over.


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