I recently had to replace my kitchen hot and cold taps.
I have a gravity fed system.
The cold was easy but the hot water tap wasn't.
I turned off the mains water, turned off the stop cock from the cold storage tap to the cylinder and opened the hot taps upstairs and down to empty the cylinder tank.
The kitchen hot water tap just didn't stop running, I left the hot water tap running for about an hour because I thought it would eventually stop but it didn't.
Am I missing something really simple?