Hi all,
No, the "Eheim Classics" don't have a prime button, you can get a "priming attachment" from Eheim, but I've never bothered. I don't bother with the double tap on the top hose either, I just have a straight run of hose from the outlet to the spray bar.That is partially why they are such good filters, there is very little to go wrong, they last for ever, you can always get the bits for them and the water must pass through the filtration medium. I always think of Clive's great description for external filters "
just a pump in a bucket". I've got both a 2211 and some 2213's and they are great little filters.
To prime the filter, connect the bottom (inlet hose) to the filter body, and make sure there is a reasonable drop from the inlet (immersed in the tank). Don't turn the filter on, open the double tap and the water should flow under gravity into the filter body, (you can see it filling through the translucent green body of the filter). When the filter body is full, insert the end of the outlet hose into the tank, (make sure it is under the water) and turn the filter on. A variety of bubbles and water should then come out of the outlet hose, if it only air comes out turn the filter of and suck on the hose until there is water in the outlet hose, then turn the filter back on.
Once the water is flowing freely, without too many bubbles, connect up the spray-bar, turn the filter on and off a couple of times whilst rocking it back and forward. Once it has purged the air bubbles it should be entirely silent, unless you put your ear right up to the filter head, when the impeller hum can be heard. If it becomes noisy again within a couple of minutes you have an air leak somewhere (could be the hose connectors, but is almost certainly the gasket between the filter head and body). In this case you need to take the head off, re-seat the gasket, and prime again.
After that the filter will only become noisy again if the flow into the filter head is impeded, at which time it will need a clean (you may find the bottom hose is full of debris). I put a sponge on the inlet hose, and this means the filter only needs cleaning every 6 months or so. As long as you keep the inlet hose under water while you take the sponge of for a rinse you shouldn't have any problem with air bubbles. If it is a very bare tank you may struggle to hide the sponge, and if you do have an internal sponge, and do more maintenance, it might be worth using both double taps, as these make it easier to remove the filter body.
These are the sponges I use, I sew them up from a square of PPI10 sponge with nylon thread, and slip them over the inlet strainer, they less than a pound each and they take about 5 minutes to sew up, I bought my last lot of sponge from here: <
http://www.pumpsandspares.com/other-items/miscfoamsbrushes.php>, the "TFGS12000" . This is the finished filter sponge.
cheers Darrel