Heating system is a Honeywell Smartfit, its an all in one digital timeswitch/thermostat etc. The water is set to 60 degrees.

The hot water system was drained down about a month ago when I had the shower taken off, re-tiled and refitted. Not too sure if it was making the noise before then or not though. The hot water runs fine though, no splutters, and plenty of flow. Only thing I would say is that I've got a thermostatic mixer shower, and since it was refitted, you seem to have to have the dial thing set more towards cold than it was before?

Cheers

Rich