I have a Par Max 12v 11ltr 25 psi water pump that pumps water to my sink and my shower. I have a mixer tap on my shower so I can plumb in my washing machine. Today I have no water coming to the shower - the pump kicks in for a couple of seconds then stops. All other taps work including the washing machine when I switch the mixer tap. If I disconnect the shower pipe, the tap works but when reconnected, the pump does not kick in... Anyone have any idea what on earth is happening? It was absolutely fine until today. The pump was fitted a month ago with no incident until this morning.