I installed a new faucet Dec 7, 2007 in the kitchen which is on the second floor of a three level single family house.--it is a single handle lever type (Pegasus). The faucet worked fine for about 70 days and then the water flow decreased to a trickle... immediately, no gradual slowing. I replaced the catridge in the faucet with a new one and the trickle became worse. If I remove the nozzle head, the flow of water is very slight. There are no kinks in the flexible stainless steel supply lines. All five (5) other faucets in the house work fine. The kitchen faucet is directly above the water heater (gas) and the dishwasher hot water which comes from a closeby copper pipe works well with great pressure. What could be causing this? Advise greatly appreciated.