I bought a new faucet for the kitchen sink and was preparing to install it. I can shut off the cold water valve, but when I tried to shut off the hot water valve the knob turns but it almost feels like it might be stripped, so it doesn't turn off the water. I'm wondering if I can basically take off the knob to the hot water valve and then use a wrench to turn off the valve without shutting off the main water supply to the house. I can't really tell if it's just the knob that needs to be replaced or the shut off valve itself. Any help would be appreciated! :-)