I have a shower that is upstairs and there is little to no hot water pressure and the cld is slowing up over time... I am sure that there is calcium or lime in the line. My question is how do I flush so I can once again take a shower because as it stands there is not enough pressure to force the hot water up and out of the shower head and to get a bath there are times I have to run straight hot water for like 40 min or so just to get a bath. I just want to take a shower again and wash my hair without washing it in the sink in the kitchen. Some one PLEASE help me!!

Before we can help we'll need the brand name of the valve, its age and type,(one handle or two knobs). Back to you, Tom