I recently replaced the kitchen, and replaced the piping leading to the new tap. Strangely, I now have an intermittent supply of water coming straight off the mains (the kitchen sink is the first water outlet after it enters the house). Sometimes it is only the kitchen sink that is affected (both hot and cold), at other times the bathroom taps are also dry, and at other times it works perfectly. The only mistake that i can see that I made is that I forgot that the I'd bought a directional stop-cock, and so put it on upside down. But I can't see how that can be the cause of the trouble. Any suggestions??? many thanks.