When you turn on and off faucets in your home, do you sometimes hear a loud banging noise in your pipes? It might be disconcerting, but it is not very uncommon. The reason for the sound is commonly called water hammer, and it happens when your water bangs against the walls of the pipes. Over time, this will damage your pipes, so the problem needs to be resolved as soon as possible.
Since the problem mainly comes from the pressure in your pipes, air chambers are installed to give the pressure somewhere to vent and stop the water hammer, but if these pipes are filled up with water for some reason, they will not work properly. Air chambers are vertical pipes and should be full of air, but at times, water could fill them up.
To drain them, you can shut the main water supply off and open all the faucets in your home. This will allow air back into the air chamber, and it should once again function as a protection against a water hammer.