Reduced hot water volume.
My gas hot water heater is 10 years old and I replaced the temperature release valve 4 months ago since it was non functional and covered with a clear salt-like material. There is no pressure reducing valve or any kind of water softner. My hot water pressure has been reduced approximately 75 percent, cold water pressure is phenonmenal. The only thing I have done is routine maintenance which was flushing the tank for sediment. Water comes out clean. Does anyone have any clue?