I confess I'm guessing a bit, but my understanding is that the pump will be controlled by a pressure sensor that will (or should be) located between the pump and the shower. Thus, when you turn on the shower, and release some of the pressure, the sensor turns on the pump.
On which side of the pump did you replace the hose: input or output? If it was on the output side, check to see if the sensor was replaced correctly.
cycleboy
February 2009
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