The heater elements in an electric showers burn at a constant rate . So you adjust the temperature of the shower by increasing or decreasing the flow over the elements. When you move the control towards hot you are simply reducing the flow , this is how they work. Low flow is more noticable in winter as the incoming main is colder. However if it has got noticably worse have a competant person check the inlet filter. If it has not been serviced for six years it may be partially blocked. Plus the other chap was right, clean the handset. Other possible cause`s could be limescale if you live in a hard water area.
Alan, December 2008
