Advice on noisy Tunze 6205's

[Deester]

Hello,

I recently purchased and installed 2 x Tunze 6205's. They have been in use approx 12-14 days now and are very noisy ... a loud hum with a slight chatter at times.

They are installed on 12mm glass that has a 6mm acrylic back wall siliconed to it for a total thickness of 18mm. When the pumps are removed from the silence clamps and held in the hand the noise is the same. I was kindly supplied with new prop/shaft assembly's by the supplier which once installed have again made no difference.

Tonight I have dismantled them again to check for any obstructions ect (as per suppliers instructions) and have noticed that in the motor block magnet well/hole (where there magnetic prop sits inside of) that there is scoring/scratching on the inside wall ... indicating that there is wear and contact between the mag propellor and inside wall of the motor block. The scoring/scratch is noticibly deep indicating that there is some serious contact at play.

My question is ... is this considered normal or is it a fault ?

I have included a YouTube video of the noise generated for reference. Both pumps are very noisy and can be heard three rooms away at the other end of the house :thumbdown From all that I have read they should progressivly get quieter and be near silent after 2 or so weeks run in time. In the time I have run them they have not reduced in noise level.

I can try to get a picture of the scoring/scratching in the magnet block well, but it's a hard pic to take.

Here's the Youtube clip ...

http://www.youtube.com/watch?v=QpRvLVQiH_s

any advice greatly appreciated.

Dee.

 

[Aquadepot]

Dee,

Sounds like something is mis alligned, please ship them back to us and we will repair or replace.

Graeme

 

[rvitko]

I only want to comment for any other readers in the future.

I cannot imagine a scenario where the magnet rotors would touch the side wall. The pump would most likely not run in this condition. It would be possible if a rubber bushing at the end of the shaft was missing for the rotor to have a wide orbit and periodically rub the side wall. Most scratches are caused by a foreign object entering the pump and being dragged by the rotor, the most common being gravel.

Most noise issues are caused by a bent shaft, it is not impossible for a new shaft to be bent.

 

[Aquadepot]

Thanks roger,

Yes I thought the same as the impellors were replaced we will need to test the pumps first hand.

Graeme

 

[Deester]

Dee,

Sounds like something is mis alligned, please ship them back to us and we will repair or replace.

Graeme

Thank you Graeme, I have sent you a PM (on MASA):thumbsup:

I only want to comment for any other readers in the future.

I cannot imagine a scenario where the magnet rotors would touch the side wall. The pump would most likely not run in this condition. It would be possible if a rubber bushing at the end of the shaft was missing for the rotor to have a wide orbit and periodically rub the side wall. Most scratches are caused by a foreign object entering the pump and being dragged by the rotor, the most common being gravel.

Most noise issues are caused by a bent shaft, it is not impossible for a new shaft to be bent.

Hello Roger,

Thank you for replying.

Looks my assumption is incorrect then :hmm4:

I thought due to the inherent design of the Tunze that it would not be possible for contact between the rotor and motor block and assumed by the look of the wear/scoring that that was the case ... my mistake.

I have inspected the internals of the 6205's many times and have not found any obstructions inside, I am also using a bare bottom tank with no substrate/gravel. I am at a loss as to what the wear could be from.

I have replaced the rotors and shafts on both. When I first received the 6205's the shafts did not "roll true" so I requested replacement. the new ones do "roll true" and the rotors now spin freely and feel balanced.

I will post pictures of the shafts an rotors, but I am certain that they are installed correctly. I will also post a picture of the scoring on the motor block for reference.

Thank you for your time, it's appreciated.

Dee.