Temperature Control on Shower - Either too Hot or too Cold Drainage and wastage systems and plumbing help, advice and answers

[KGB Production]

we moved house at the end of last year and one of the showers (mains) was running either very hot or very cold. I followed the instructions in the manual to adjust the temperature after removing the temperature control knob to no avail. I called a plumber who said he was too busy to come out before Xmas but advised that the cartridge would need replacing. I duly purchased a replacement from the manufacturer and followed the instructions to fit it myself - success........for a month or so. Now the original problem has returned. This time after removing the temperature control knob and trying to recalibrate the temperature settings, all I can now get out of the shower is cold water. Very grateful for any help.

[stoneyboy]

KGB Production,
Your problems may be because you live in a hard water area and scale is seizing up the thermostatic mechanism or there may be debris entering the valve. Are there filters on the inlets to the valve? did you flush the system before fitting the new cartridge? Not really questions just pointers as to where you look next.
end