Hi All, I have an odd problem, we moved into our house about 5 years ago and have always had a problem where the bath tap runs from scorching hot to luke warm after it's been running for a minute, despite the heating being on all day, this process can be repeated after switching off for about a min. I think the whole heating system is the original one from about 30 years when the house was built. It's a conventional gas boiler (not combi) and for some reason we have a large combination hot water cylinder, despite it being a 4 bed house with loft (no separate cold water tank). The other taps, en-suite shower, around the house all seem to run hot water continuously with no problem. Any suggestions regarding the problem would be welcome, thanks.