Yes - its just from the hot tap. There's about a teaspoon of water (or perhaps less) that ouses out when the tap is shut off - then it stops. There is no water leaking down the pipework (under the worktop) from the tap.
Sorry - its 6 years old. As an aside, I replaced the main 'boiler' component about 2 years ago.
Thank you - I have to go out just now for the rest of the day. I will take a look at the information you sent through and reply tomorrow. Thank you for your help meantime.