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get a pressure gauge from home depot, put it on a laudry sink, while at home depot, ask one fo the plumbing guys how to raise the pressure, they will show you what a pressure regulator looks like and how to adjust it, its also usually located near the meter in the house. it might be going bad, if it is, replace it if you are handy, if not get someone to help you, like a plumber.may also be yor water tank, but i doubt it, on the bottom of the water heater is a drain valve, open it and see what comes out, if water comes out, its probably not filled with sludge and shouldnt be that. for pressure anyway, as far as being cold, touch both pipes connected to tank, if both are very cold, then tank may be out, pilto lighting instructions are on the tank, bend down and look in window at bottom and see if you can see a flame, if so, turn temp up to see if it ights, if not, something isnt working and you need a pro to diagnose it.