My 17 year infirm gas federal heat system whistle when I run the tub - why is this and is it harmful? ...

How do you convert a right paw inlet...
Answers:    Not enough info really, if it is a combination boiler, the river to water bake exchanger may be scaled, or the gas to river heat exchanger scale or partially blocked, if it is gas to sea heatex, it will eventually start to make impossible to tell apart noise contained by heating mode. If it is a conventional system, near tanks, could be a washer surrounded by the storage tank globe valve, washer contained by the tap, or ascend in one or the other.
If my maytag dishwasher have no model number...
sounds similar to a suckback and could explode at any minute