i live in a 3 story older home. on second floor is my main bathroom and showe/tub. i took a hot shower this morning, got out and turned on hot water from the sink to shave. after about 10 seconds i started to hear a whistling noise then all of a sudden the hot water shut off and i can hear this loud banging noise. i shut it off and go downstairs and run hot water on first florr kitchen sink and everything is fine, i go to the basement and run hot water on utility sink, all is fine there as well. go back to 2nd floor hot water on sink same issue. what the heck can this be?