About three weeks ago my, water heater died and we had it replaced. When they did so, they had to add a tank on the top of the water heater that was not their before
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not the exact one but its basically the same thing). Its now required in my city due to some water meter changes the city made. Anyway, as soon as the guys (yes I hired someone) finished the toilet started to hiss. I don't think that an abnormal amount of water is going from the tank to the bowl so its not a constant refilling issue. If I close the shut off value the noise stops, and when I open the value the noise starts again. If I leave the valve open for a few days the noise gets louder (it gets to the point of annoying and then I close the valve). Here is another strange point. I was changing a hot water shut off value in the kitchen, and I noticed when I close the hot water valve coming from the water heater the noise in the toilet jumped.
Anyway, whats going on to make the hissing noise?
Should I just get one of those replacement kits at Home Depot or Lowes and see what happens (noticed they are less than $15).
John