eheim external cannister rattling noise

[boxedfish]

what is the cause of eheim external cannister rattling noise when powered on? In my case, i have primed the cannister properly but the motor/impeller area makes a rattling noise constantly. i checked the impeller, the blades are all intact. impeller shaft and brushings are all there and secured. Can it be the internal of impeller spoilt already?

[eviltrain]

i guess there is still air in the canister. try to tilt the canister to let the excess air flow out of it while the canister is on.

[boxedfish]

did that already.

[eviltrain]

then could be the inside of the impeller is broken.

[boxedfish]

guess that is the main reason. Anyone got any other idea why to share? is it possible the internal of the motor making this noise?

[celticfish]

Its the impeller blades hitting on air pockets.
Not likely the "motor" in the head unit (there are not moving parts in there).
The moving part is the impeller by magnetic field.
Either its not primed well enough or the flow rate has gone below optimal or there is a leak somewhere in your piping system.
Flow rate drop usually happens when the filter is clogged or the filter is placed too close to the water level.
Ehiem filter works mainly with the principle of gravity feed to the filter.
Hence the lower the filter is to the water surface the better (within limits of course).

[boxedfish]

thanks for the mentioning a few other possibilities. water level is correct, which is much below the tank.Later i will use a working impeller from another cannister to test if it is really the impeller problem or not. will try to clean more thoroughly the filter also.