We have very low hot water pressure at all faucets, although our cold water pressure is fine.Our 40-gallon hot water heater is over 15 years old. I drained some of the tank to remove sludge and it actually seems worse. Could the hot water heater cause this, or is there something else that might be the culprit? Our home is unique in that one main water line splits into a hot water tank for the in-law wing and then continues on to our hot water heater. The hot water pressure is fine for the in-law wing.

Replace heat trap nipples on water heater.