Our gas powered shower has been gradually needing an increase in temperature over the last few months in order to have a warm shower. Originally a 32 degree shower was perfect, but gradually we have had to increase this to have a normal warm shower. Currently the temperature gauge is at 50 degrees and won't go any further. Within a day or so, we will be having cold showers.
I've tried re-pressurising the boiler, and all seems normal there. Water coming from taps are normal temperatures.
What else could it be?