Eheim 2076 Air Issue

[juddscrud]

Hiya all,

Ive installed an Eheim 2076 to my 170 litre tank, and placed the intake at the nearest end closest to the filter, (approx 3 feet of pipe), and the outlet at the other end of the tank using a longer length of pipe (approx 4 - 5 foot) to the spraybar which is placed under the surface.

All was well for a few days, but now I'm getting air drawn into the filter from somewhere, which causes excess noise in the filter and de activates the auto flow rate feature

The filter doesn't seem able to 'auto vent' the air so I have to use the priming pump to expel the air through the outlet once a day.

Does anyone know where the air could be getting drawn in (no sign of leakage from pipes) and also how to 'auto vent' the filter?!?!

Is the outlet pipe too long to vent the air or could it be down to the spraybar being fixed under the surface that's stopping it from self clearing?!!?

Thanks for any help on this guys!!

George

 

[rabbut]

Ok, switch it off and allow it to stand with all taps open for about 1/2 an hour. If there is a dodgy seal allowing air in, after this time you will see some speapage of water from the seals.

Is there any air getting up the inlet pipe, say from an air pump?

If there is no seapage or air entering from the tank, it's just air trapped in the media. Switch her back on and shake the filter/tilt it onto angles to free the trapped air. Once it's out it should settle down

All the best
Rabbut

 

[juddscrud]

Ok, switch it off and allow it to stand with all taps open for about 1/2 an hour. If there is a dodgy seal allowing air in, after this time you will see some speapage of water from the seals.

Is there any air getting up the inlet pipe, say from an air pump?

If there is no seapage or air entering from the tank, it's just air trapped in the media. Switch her back on and shake the filter/tilt it onto angles to free the trapped air. Once it's out it should settle down

All the best
Rabbut

Thanks for the reply Rabbut

I'll try the stand idea, that makes a lot of sense when you think about it!!.....I have a powerhead on the opposite end of the tank but by the time the flow/air has reached half way along the tank it's dispersed and not visible to the eye.

I've bled all the air out of the head a few times only for it to return after a few minutes, so I cant see it being residual from the media....but I'll try the stand idea and post results

 

[juddscrud]

Just a quick update, Ive stood the filter for an hour or so and no signs of leakage or anything, also ive turned off all my 'air producing' items and theres still a constant build up of air over a very short period of time

Iv'e tried rocking the filter and the air gets expelled, but then builds back up again!!

If I run the filter on manual 'max' output, the yellow warning light comes on and stays on, but the air generally gets expelled through the spraybar in small bursts. On a lower output (5 green lights), the yellow goes off but the water stays in the filter rattling about!!

Obviously I could just run on constant 'max' ,but the auto adjust feature would be inop!!


thanks again for any input!!!

 

[rabbut]

If there was air getting in at a seal, the filter would leak a small amount of water if left to stand, so a seal is unlikely to be the problem... You have applied Vaseline/Silicone O-ring grease to all seals and checked that all hoses are on their mountings correctly haven't you?

Where abouts are you based? May be a local can call in and have a look to see if they can fix the problem for you if you are new to externals?

All the best
Rabbut

 

[juddscrud]

If there was air getting in at a seal, the filter would leak a small amount of water if left to stand, so a seal is unlikely to be the problem... You have applied Vaseline/Silicone O-ring grease to all seals and checked that all hoses are on their mountings correctly haven't you?

Where abouts are you based? May be a local can call in and have a look to see if they can fix the problem for you if you are new to externals?

All the best
Rabbut

Hi Rabbut,

Thanks again for the reply .... I have checked all the seals and hose connections and used silicone and all seem ok (no leaks or visible entry points!!) so this has got me scratching my head a bit!!....Ive used an external for a couple of years now (last one was a Hydor prime canister), and had no issues with that.

One thing I seem to remember reading somewhere was that if the hoses are too long then that (may) lead to problems....I might try getting a shorter length of pipe and try moving the spraybar closer to the filter end and see if that eliminates the problem

Thanks for the help though!!!..much apreciated!!!!

G

 

[Schmill]

also ive turned off all my 'air producing' items and theres still a constant build up of air over a very short period of time

Iv'e tried rocking the filter and the air gets expelled, but then builds back up again!!

In which case I would say there must be something wrong with the filter...
Air cannot just 'buildup' it has to come from somewhere... If your media is well soaked, and has been shaken, rocked & jiggled for all its worth then the air can't come from there, if you have turned off your 'air producing' items then they are obviously not putting air into the filter, which really only leaves to options:

1) The water is being boiled within the filter, forcing the 'air' out of the water, (similar to boiling water in a kettle), - very unlikely.
2) The negative pressure within the filter is sufficient to suck air in through a pipe union or a seal on the filter.

Of the two options I would say that 2 is the most likely. Although the 'stand' test will reveal most bad leaks it's not perfect. It is relying on the 'leak' being bi-directional, that is it lets stuff in (air), and will also let stuff out (water). However it's possible for a leaky seal to only leak in one direction, for example when teh pump is running an o-ring may be 'sucked' out of its correct position, thus allowing air past it and into the filter, however once you turn off the filter and do the 'stand' test, the water inside the filter now pushes one the o-ring slighty, causing it to re-seal the leak.

Althought it's not want you want to hear, rule out the impossible, then whatever is left, however improbable, is your answer.

As to how to fix it or even detect where it is though I do not know...

Perhaps as a test place your hand over the inlet pipe so as to seal it, and then listen around the cannister for a hissing to see if you can work out where the air is getting in, but not sure how well that will work... listening for a quiet hiss with a noisey filter motor running...

 

[rabbut]

This is an Eheim pro, not a Fluval, you should hear air entering the filter with your method over the motor provided air does not get to the impeller and cause cavitation