Weird water hammering for over an hour.

[Melissa2007B]

We weren't using any water when this happened. We're in a residential neighborhood and this is a IRC modular home, with PEX. We've been here since 2005 and never heard anything like this before. I heard it when I was walking by the laundry room where the water heater is. It went on for about an hour. I called the water department emergency number and they sent a guy over, but it had stopped by then. I showed him both of the videos that I captured on my phone, but he just shrugged and said "it's not out fault" and they didn't know what was causing it.

What could do this? Like a neighbor using some kind of pressure washer with pulses?

https://denverprocessservers.net/TEST/Water pipe vibrating due to pressure hammering 1.mp4

 

[Reach4]

Weird. Got a pressure gauge to stick onto a garden hose spigot to see if that needle wiggles too?

I am picturing some valve triggering an oscillation. You don't have a PRV (pressure reducing valve), do you?

 

[Sponsor]

 

[Chucky_ott]

impulse lawn sprinkler ?

 

[Melissa2007B]

Weird. Got a pressure gauge to stick onto a garden hose spigot to see if that needle wiggles too?

I am picturing some valve triggering an oscillation. You don't have a PRV (pressure reducing valve), do you?

No, and it was only for about an hour, that one time.

 

[Melissa2007B]

impulse lawn sprinkler ?

Not around us. We're in Denver and it's late October. No one is watering.