The reason for all the discussion about where the water heater is: My toilet whines and groans when flushed and the sinks and shower whines when used.
I've read on the internet and conversed some of my "family" here at the park and they suggest I use vinegar and baking soda to clean the lines. BUT, I need to turn off the water heater first.
Thanks to everyone for all your help. This is a terrific forum!