I have a Triton T80 (8.4KW) electric shower which just isn't giving water as hot as it did at high temperature, certainly not as hot as during the summer anyway.
The shower has four settings for power, off - cold - warm - hot and there is also the rotary temperature control.
With the power on hot and the temperature control near high, the water isn't very hot anymore.
I don't know if this is associated with the very cold weather we are having or an electrical problem but would like to know.
The shower is fitted against a wall without cavity wall insulation, not that this has mattered in the past, and I live in suburban Manchester which hasn't been too badly affected with snow.