I hear a loud water hammer noise when the water flow to my Bryant humidifier #HUMMBBLBP2417 shuts on or off (I can't tell which). I'm pretty sure it's the humidifier because I don't hear the noise when I turn it off. I hear the noise on the first floor of my house coming from the basement but when I go down to the basement to find the source, I can't. I have an expansion tank on the cold water line near the hot water heater. My furnace company replaced the humidifier solenoid valve and I installed a Sioux Chief mini water hammer arrester on the humidifier's supply line but neither of these have worked. Does anybody have any ideas on how to fix my problem? Thanks.