Pump noise question

[niels123]

In a lab, we have a tank with demiwater with a glass cooling spiral (in a condensor) connected to an Eheim CompactON 600 pump. It's running 24/7. The water tank contains a second pump (Eheim CompactON 2100) that also runs 24/7 pumps the water through an aquarium cooler that cools it down to about 46F.

The set was working perfectly for 3-4 months, but now the CompactON 600 makes a terrible rattling noise (see attached sound recording). Plugging and unplugging the power cord of the pomp a few times helps for some time, but the noise always comes back. I have exchanged the unit for a new one, but now I have the same issue again.

On the other hand, my CompactON 2100 does not have this issue. What could be the issue? What would you advice? Exchange the CompactON 600 for a different model, and which one?

 

[vetteguy53081]

In a lab, we have a tank with demiwater with a glass cooling spiral (in a condensor) connected to an Eheim CompactON 600 pump. It's running 24/7. The water tank contains a second pump (Eheim CompactON 2100) that also runs 24/7 pumps the water through an aquarium cooler that cools it down to about 46F.

The set was working perfectly for 3-4 months, but now the CompactON 600 makes a terrible rattling noise (see attached sound recording). Plugging and unplugging the power cord of the pomp a few times helps for some time, but the noise always comes back. I have exchanged the unit for a new one, but now I have the same issue again.

On the other hand, my CompactON 2100 does not have this issue. What could be the issue? What would you advice? Exchange the CompactON 600 for a different model, and which one?

Pull the impeller and check the magnet for scratching/scoring and the shaft hole for any foreign matter or snail shells within and assure the shaft rod is straight and bushing not missing

 

[theMeat]

Don’t have experience with ehiem compact but ehiem hobby pumps are pretty bulletproof. A dc pump will run quieter and cooler than an AC

 

[niels123]

Pull the impeller and check the magnet for scratching/scoring and the shaft hole for any foreign matter or snail shells within and assure the shaft rod is straight and bushing not missing

snail shells
The tank has ultrapure water and nothing else. No fish, no life, no plants, just water that is far too pure for drinking because it doesn't contain any salts whatsoever.