Water pump 'hammers' after use

[Scampi30]

The hammer effect is a result of a pressure wave resonance, so adjusting the pressure may make the noise less, though it will not remove the base problem of trying to compress the in-compressible till the magic cut out pressure is reached. Fitting an expansion vessel allows the cut off pressure to be reached with an air buffer to handle the pressure impulses from the pump. In reality an expansion vessel of some kind should always be present in a positive displacement pump system

This would be my solution. Water system should always have an expansion tank to stop hammering and the annoying short pump burst when you are trying to sleep. They are easy to come bye and don't have to be any particular make and are available from chandlers or caravan shops.

 

[Nemos Dad]

Thanks - also, excellent service from Johns Cross

Thanks to all for the very helpful suggestions. Tweaking the pressure switch adjuster has certainly improved matters. Still a bit of a knock after turning the tap off, but nowhere near as bad. At least the pump doesn't trip itself off now! I will definitely give an expansion tank a try as they seem inexpensive and easy enough to fit - from Johns Cross of course!
Also want to comment on the excellent customer service from Johns Cross. I ordered an awning accessory on line last Monday afternoon and it arrived on Tuesday morning. As mentioned earlier in this thread, full members get a discount from them.
Pete