Pump Differential

[Chalmers7]

Working on a commercial system and the Grundfos 32-80 single headed pump has a gauge before and after both saying 2bar.

the pump is spinning and no circulation is happening,

both circuits of the header have the same problem but a third set of pumps show 3/4 bar differential.

does anyone thin k this sounds like the pumps shot????

[WHPES]

Are you sure the pump is spinning and you are not just feeling a buzzing from it? If it isn't, then the condenser (capacitor) is likely shot and so replace it. I think they are 2.5 microfarrad but you would have to check.

If the pump is actually spinning, check the pipe circuit. Could a bypass valve be too far open?

If the pump is spinning but sluggishly, then the motor windings have deteriorated and I'm afraid it's a replacement.

To check for sure, take the pump off. rig it up to a header tank full of water and run it. If you can place your thumb over the end and stop the flow, it's the motor.