Every time I would turn on our power our water pump would run constantly. I'm now pretty certain it's because our outside cold water knob is broken. Before I buy a replacement does anyone have any experience fixing this? When I try to screw it back on I can get it threaded but then it will never stop turning off or on. I can get it back off by lightly putting it and unscrewing it again. Screw it back on and it never "catches" and I Can turn it to the right as long as I want.