We purchased a new, but off-brand (made in China) shower faucet, and had it installed by a plumber. Now we hear a water hammer noise near the new valve every time we open or close the new faucet or any other faucet in the house. The plumber came back to check it, and said they think it is the new faucet valve. We obtained and installed a new cartridge, but the noise remains. The hot and cold copper supply lines are secured to the wall framing, and each side has vertical piping installed as air-filled buffers. I've tried draining the lines to "recharge" the air buffers, but that didn't help. Is it possible that the valve could be making this noise? Should I try installing hammer arrestors or just replace the valve? I can't imaging that it matters, but the plumber also installed a new main shutoff valve to the house. Any help is appreciated.