The kitchen tap handle just spins and doesn't grip to the valve to open/close. I had the cartridge/valve replaced 6 months ago by a plumber due to a slow drip. It still has the original cap/handle. It seems the new cartridge spindle is shorter than the original was and the cap is no longer gripping to it. I tried to replace just the handle/cap but the caps I've tried have been the wrong size. So then I tried to replace the whole hot cartridge side but I'm unable to find the hot water/mains stop cock! I think a whole replacement for the hot tap valve is required.
But if I can upload a picture, I wonder if anyone is able to guide me on what cap/handle to purchase to fit the spindle/cartridge/valve...!