If you have lost hot water pressure throughout your home it could be due to several causes.
If you have galvanized pipes they may have become rusted. Another cause could be mineral buildup especially if you live in an area that has hard water. If it seems to have happened all of a sudden then what has probably occurred is that pieces of your pipes have broken off and are creating a blockage.
If you have a standard water heater one way to test this is to attach a water hose to the bottom and test the flow. If the flow is not good your water heater could be full of sediment or the blockage is at or before the water heater. If the water does seem to flow well then the obstruction is somewhere before the first piping tree. You can attempt to loosen any debris by turning on any valves you have in the areas listed previously.
Another possibility of the loss of water pressure could be a a clog at the source of the hot water. If you have a standard tank water both the inlet and outlet port could be clogged.
It is also possible that a valve is closed or even broken.
If you have a standard water heater and it is over 7 years old you should consider getting it replaced.
If you need a Greenville plumber to get your water pressure back to its normal levels give us a call at 864-663-6105.