what wheel thing? do you have a cold water tank? if so at the bottom there will be 2 valves usually red handled one of these will be the supply to the hot water cylinder the other will feed the bathroom etc turn both of if you like and after a few secods there will be no hot water from tap, if you have a combi boiler turn of the cold inlet supply beneath the boiler which will shut off the hot supply
alex, December 2005