An enlarged prostate is also known as benign prostatic hyperplasia (BPH), which is generally not associated with any prostate pain. However, an enlarged prostate can cause problems with urination.
When a homeowner turns on a faucet, the cooled water sitting in the pipes circulates to the faucet first, so the homeowner has to wait for hot water. A hot water circulation pump sends cool water in the pipes back to the water heater through a return line. A pump circulates this water through the water heater as needed to keep it hot. This continuous loop of water through the water heater ensures that hot water is always available.
It could be from a number of reasons. Normally, hot water pressure out is determined by the pressure of the cold water going in, of course. However, excess floating scale and debris from the inside of the water heater could have clogged the various hot water sides of faucets, washing machine mixing valve, etc. Usually, you can hear this debris bubbling when the heater is on.