Humidifier water hammer

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.

Water hammer is caused when flowing water abruptly stops and the change in velocity causes the piping to shake if it's not secured properly. Look through the pipes you have access to and make sure they're securely fastened. If not, add some more clamps to secure them. Contact the manufacturer of your humidifier.
http://www.bestsellingreviews.com/Personal-Care/Humidifier/

you should really take a look at the pipes that are connected to your humidifier if you want to fix your problem, you might want to tie them a little bit more if they are not tied them enough. if you see any shaking and your bolts are tied enough then apply epoxy glue to the piping.

but if your problem is a little bit more complicated than this then you should call a professional in plumbing in order to fix your situation, I remember I used to have a problem with a pipe, some potassium oxide got in there and the plumber I called got in there and he unfortunately exploded... So it is the little things that really matter in a good plumbing job, if you don't have the skill then you should not risk you life on a little thing like this.

Of course that if none of these work then you should consider getting a new humidifier.

try a spring loaded check valve

george1 said:

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.

Click to expand...

Just to be clear on this. So you're saying that you already had the banging noise and that's the reason the furnace company replaced the humidifier solenoid valve? And then you installed a Sioux Chief mini water hammer arrester on the humidifier's supply line? May I assume you installed it upstream of the solenoid valve?
What's the history of this humidifier banging noise. Is it a new unit? Or did the noise just start happening after you had it for some time?
Why can't you have someone up stairs turning the unit controls to cause it to start/stop while you're down stairs getting a better idea of the source of the sound and relationship to the start/stop operation.
Did you contact the mfr and ask them about it? See what, if anything, they have to offer for suggestions. Ask them about whether their original solenoid valve is a slow closing unit(apparently not) or does it snap close? Ask them if you could try throttle down the water supply a bit to relieve the pressure/velocity.
What size is the water connection to the unit? I assume it's small.