I live in a 3 storey house and have a Rothwell mixer valve shower on the 3rd floor fed from a Combi boiler on the ground floor. The shower was installed about 8 years ago and worked OK for a while but now only gets luke warm at best and then suddenly goes cold. How can I adjust it or is it an experts job. One other factor - I live in a hard water area (Wiltshire) so could this be a factor even though I have an in line anti-scale cartridge installed.

Peter Benns, October 2008

No matter how many water descalers you fit the valve will be clogged or if not the valve the shower head you need to dismantle the valve and clean it out check for inline filters as well. you will find these are probably gunged up if this fails you could be looking at a new cartridge if the shower mixer is type with replacable cartridge also check any isolation valves which should be fitted .They may be clogged

Steve the plumber, October 2008