Shower pump question

Grumps · 2008-10-08T19:04:50+00:00

HiMy father-in-law has just installed a Stuart Turner pump which he's had lying around (indoors) for about 4 years.He's plumbed in the hot and cold feeds and outlets, and the wiring has been done by (or checked by) a sparks.When he turns the water on, both the hot and cold flow through the pump and out of his shower head, but the pump only makes a humming noise and gets hot (apparently).He removed it today for inspection and noticed that, upon removing either end cover (to access the impeller bit), that it seems to be stiffer than would be expected when trying to turn. I had expected the motor to spin freely, but then, what do I know!?And, as an aside, how do the flow sensors work? They just seem to be sealed plastic boxes on the end of a wire.Ta.