Pipes clicking and tapping when hot water runs through, it's driving me nuts!

[MinimalistMommi]

I'm guessing it's the pipes expanding?
The rhythmic tapping keeps us awake so we're unable to have heating on over night!
Help!

I think you mean the radiator pipes

it might be under the floor, where they are tight against joists and are rubbing. Correct method is to enlarge the holes or notches and wrap a little felt round the pipe to prevent it touching.

If the radiators themselves are creaking on their brackets, radiators have for at least 20 years been sold with little U shaped plastic fittings included, which fit between the hanging plate on the rad, and the slot in the metal bracket. The plastic slides silently. The radiator has to come off to fit them. a plumber might have a pocketful of spares, I don't remember ever seeing the U's sold on their own, but perhaps a radiator seller would have them.

You might also consider turning the boiler thermostat down very low overnight so that it never goes off but just ticks along keeping the radiators a bit warm.