Can someone help ? I have an airlock (air hammer for the US contingent) in my mains fed toilet system. I have two toilets, that both work fine, but after flushing either of them, I get an awful noise... that can take as long as 30 seconds to occur... coming from the system. I live in the UK, in a house built in 1886. We have pretty strong mains pressure. One toilet is upstairs, the other is at ground level. Turning on the cold taps stops the noise, turing the water off that re-fills the cisterns (unsurprisingly) stops the noise. I have never heard of an air arrester, and wouldn't know where or how to get one ! Can anyone tell me what I need to do to stop this from happening ? It's really annoying, both for us & the neighbours, or do I just submit & get the plumbers in ? (Reluctantly.. as they're really expensive & always find other things that need doing as a matter of urgency !)

You need air chambers to absorb the shock. I have put up images of a air chamber and how they should be installed. Since the 60's here in the states we have install air chambers on all bathroom sinks plus the kitchen sink to address the problem of water hammer. A air chamber could be installed on the toilet supply coming out of the wall that would absorb the shock and stop the noise. PS. Water hammer puts a strain on the joints and elbows in the water system. Good luck, tom