* It could be your toilet. When you open the faucet, the pressure at the toilet changes and the toilet valve starts to vibrate causing the banging.
* typically it happens when you turn the shower on.
* Turn off the water at the toilet then test. If you have more than one toilet, turn them all off.
* Generally one toilet will be the culprit.
* Replace the valve that the float operates.
* Send me some feedback on your results.
* Good luck… Adios… Jaspr…
Jasper Castillo