I know about water hammer - the loud noise associated with a rapidly closing valve causing the water to slam inside pipes causing them to bang. I also know most of the solutions - arrestors, expansion tanks, securing pipes, draining the pipes, etc.
The water hammer I'm experiencing is different.
- Instead of a single loud bang, I get a rapid fire dull thump-thump-thump almost like the rat-a-tat-tat-tat of a machine gun. - They happen when just about any faucet, toilet, shower, appliance, etc. is turned ON or OFF. - When a device is turned ON, I'll get 4 or 5 rapid thumps lasting a second or two. - When a device is turned OFF (even slowly turning off a faucet) I'll get anywhere from 20 to 50 rapid thumps lasting 3 - 7 seconds. - It happens with both hot and cold water, single valve devices or dual faucet fixtures. - It happens 85% - 90% percent of the time. - I have drained the system and refilled it. I thought it helped, because it didn't happen for a few hours, then it started again. It may have just been the 15% - 20% of the times when it doesn't happen.
Anybody heard of this type of water hammer?