# Eheim Classic Humming noise



## Aqua sobriquet (17 Jul 2019)

Has anyone pinned down the cause of this? I’ve contacted the seller, hopefully they’ll send out a replacement head.


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## jkh13 (17 Jul 2019)

Check for air trapped in canister.
Check o-ring for damage
Apply lubricant to better seal o-ring
Clean impeller
Make sure flow is not obstructed entering the filter

Whenever my classic starts making noise, one of the above has been the cause.


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## Edvet (17 Jul 2019)

jkh13 said:


> Clean impeller


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## Aqua sobriquet (17 Jul 2019)

There’s no trapped air. The impeller is clean and nothing is restricting the flow. The O ring is fine, they come lubricated.
I actually ran the filter without the basket and media to check it worked and it made a humming noise then. I hoped it would be quieter in use with media in it. Even though it was the wrong kind of sound I thought it may be vibration going through the cabinet but it’s still noisy if I hold it in my hands. I can reduce the noise by maybe ten percent if I put hand pressure on the top of the casing.
There is very little vibration.

I had the exact same model many years ago and it was virtually silent in use.


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## Millns84 (18 Jul 2019)

Try coating the impeller in silicone grease. I've had a few powerheads and filters over the years that needed this just while they wore in. 

Any hoses touching part of the cabinet?


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## Aqua sobriquet (18 Jul 2019)

I’ve already greased the impeller. Not something I ever needed to do in the past but I read about it a while back. I’ll check the hoses.


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## Aqua sobriquet (18 Jul 2019)

The seller has asked me to return the head. I’ve been out all day today and when I came in it’s even noisier than it was yesterday. It’s developed a rattle as well as the hum which is even louder. I’ve shaken the canister and a small amount of air has come out but it’s still just as noisy.


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