and dishwasher into the same water supply under my sink.
Does it exist? what would it be called.
I have the hot tap unused but I don't wish to attach the dishwasher to it.
pay three times as much when it goes wrong, then you want one of these,
Selt tapping valve
You need to make sure you have a section of pipe - 15mm copper - under the sink with good clearance around it. If the pipe is pressed up tight to the wall this device wont work.
Just get a plumber in Fash. I have seen so many wretches cowering under the withering stare of their irate wives, babbling "Thought I'd have a go myself.Thought it wouldn't be too difficult."