Sssss Whooosh Crack

JamesNLA

Gotta call from a guy that I swapped out his tanked heater.

Rheem 40 Gal NG.

He has a recirc (existing) and I just changed out the check and re plumbed it back in.

Put an expansion tank on the cold side. City pressure is 60 PSI, tank charged to 62-63 PSI.

After it was installed (well, a week later) I did a follow up call to inquire. Guy said everything works great.

Now tells me that at least 20 times in a 24 hr period he hears this swooshing crack. He best described it like a sprinkler valve turning off.

He (on his own) unplugged the recirc (timer controlled) and shut the ball valve off to negate the recirc system. Tells me it improved by about 20% in frequency (20% less times this occures)

House supply has PRV but allows back flow (I still wanted to put an expansion tank as per his local code)

Will head up their tomorrow, any ideas what the hell this is?

mdshunk

Flakey PRV or check valve.