Water runs out of my tub water valve but once the connections are made, cartridge inserted, handle on, the water does not flow. I do not have the shower hooked up and it is capped on the tub water valve. I don't know why the water will not flow out of the tube spout. I have even replaced the cartridge twice. Why?

Is your complaint that water will not stop rolling counter of the spout or is your complaint the water will not flow out of the spout? What brand is your valve? Back to you, Tom