Water Hammer

[bkengr18206]

We have an apartment building client that is experiencing water hammer severly. The building is more than 30 yearsold and allegedly the condition did not start to occur until 1.5 to 2 years ago and has gotten worse. I believe that there is either a leak in the piping that is going undetected or that air is somehow entering the system thru the recirculation pump.

Does any one else have any ideas or experiences similar.

The system serves for units on two levels and has a condensing type gas water heater that appears in good condition.

The condition usually manifests it self first in the morning and after periods of very low or no water use.

 

[KRocker]

Does the service main have a PRV? I'm assuming the building is tied into the public water main. Was there any recent changes to the public service, increase flow or pressure? Were new fixtures (ie flush valves) added that required more pressure?