Yes, its a Grundfos. I can't read the model number though. It needs to be
pulled out of the drain. However, its power wire appears to be physically
attached to the industrial electrical socket. I'd tread carefully before
yanking it out.

But best of all- I contacted Grundfos who have an office here.

This is what he said- (later he also provided me with a pond contractor's
details)

base on your picture attached i presume that the pump type we are
discussing is AP35B model.

AP35B pump has a life span estimated L10 hours ( 20 degree C ) 12000hrs.
Coolant oil change every 2000hrs by continuous operation or every year by
intermittent operation. When you ON the supply, the pump is not pumping i
suspect that motor is shorted. And there is no way to service or rewind
the
motor as it is a enclosure class: IP68 motor.

My advise is to send in pump for further analysis of the failure or to
purchase a new pump. But we need your assistance in providing us the
right
pump type that you are having. Grundfos do not supply labour to dismantle
pump inside the pond as we are not certified water pond contractor but a
pump manufacturer.