Hello, every time the hot water taps throughout the building are running or every time the toilet is flushed there is a loud humming noise which can be heard outside. It vibrates the walls and the floors throughout the whole building. Would anyone know a possible cause? Plumbers have suggested pressure issues, limescale in pipes aswell but after trying to fix them it’s come to nothing.
toilet humming noise, try fitting an air admittance valve, sounds like back pressure, the system is trying hard to pull air back in after flush. do you have a vented soil stack? does it have blocked vent cap
There are several possibilities
1/ main water stopcock has loose washer which is vibrating
2/ ball valve on toilet or hot water tank
3/ faulty tap allowing air into system
When noise is present check at stopcock to see if loudest there then check toilet and water tank for noise.
Finally try turning on each tap in turn when noise is present.
Also turn off water at stopcock then turn back on wind stop valve all the way on then a quarter turn clockwise.