ticking noise when running water

If it's hot water you are running it could be the expansion and contraction of the pipes as it heats up and cools down. Hope this helps.

Water hammer at a guess but would not be sure without looking Neil

Hi, Definitely sounds like thermal expansion and contraction of the pipework. As the water and environmental temperature increases or decreases, the pipe length will fluctuate. The longer the run, the more significant the change. This can also happen if the pipes have pressure against them and the sounds can be anything from tapping, banging to dripping noises ( you would be amazed sometimes to how loud and varying the different sounds can actually be with expansion issues). Finding and rectifying the affected pipework can be as easy as tracing the sound back to where it is the loudest and starting from that point working a long the rest pipework, obviously different types of existing flooring can make this job a lot more difficult such as having to lift up a tiled or laminate flooring to access pipework. I hope you get to the bottom of your issue.

I agree to that but will expand on it, it is usually clips that have come lose that hold the pipes up that either rattle or click hope that helps they need to be retraced and clip back on