I suffered poor water flow upstairs - both hot and cold would almost dry up particularly in the morning after a bath had been run.
The feed pipe had collected brick dust and other small debris, restricting the inlet flow and the draw-off was eventually defeating the flow rate into the tank - after a bath had been run the outflow was dependent on the poor flow into the header tank.
My solution was to fit dual inlet valves to the header tank, each with its own ball float and to put a filter into the rising main with a stop valve immediately above and below - so the filter could be removed and cleaned.
No problems after that.
Peccavi
July 2009