About a week ago a load humming noise started to come from my water pipes. The noise would last for no more than a few seconds but so loud that it would wake us up at night. There seems to be no obvious reason to this, its not after we shower or wash clothes. Can you said some light on this matter for me?

Thank you

Could be a bad fill valve on a toilet or a ice maker. A vinbrating washer or seal can make a big noiuse. Try shutting down the suplly stops to different toilets and then the ice maker to try to isolate the problem.

Ball gave you the best places to start. Do you have a water softener. Ive had bad valves in water softeners make this noise also. Does it seem to happen at the same time every night, possibly when water softener is set to regenerate? Just a thought. Please let us know what you find.