hi...just joined so i hope i can get some help.....we have had anew bathroom fitted and very pleased with it we are!!the shower and cubicle etc were from better bathrooms,excellent service..but since it was installed,in december we are on our 3rd thermostatic cartridge,cannot find out from suppliers what the problem is.hot water to the bathroom is fine,but not in the shower.nothing visible on the cartridge of any faults,just wondering if anyone can help?