Spent 3 hours chasing a water hammer issue in a 4 story office building

Went to a job in Austin last Tuesday for a tenant complaint about banging pipes. Checked the main water pressure first and it was fine at 60 psi. Then I spent 2 hours opening up access panels looking for loose pipe supports or air chambers that might be shot. Turned out the PRV on the roof was failing and sending surges back down... took me another hour to get up there and confirm it. Has anyone else had a PRV go bad without the pressure gauge showing it?

2 comments

2 Comments

mason_knight9d ago

Yeah, the PRV on the roof was my first thought too after I ruled out the simple stuff. I had a similar thing happen in a three story building where the gauge looked fine but the PRV was chattering under low flow. Ended up replacing it and the surge stopped. Next time I'm just going straight to the PRV if the pressure readings don't match what I'm hearing.

wesleyburns9d ago

Hold on, is it really that common though? @mason_knight, I feel like we might be jumping the gun a bit here because I've had gauges lie to me for other reasons like a bad check valve or a partially closed ball valve that mimicked the same noise. Nine times out of ten I still find a loose support or a chunk of crud in a valve before it's the PRV itself.