So last night, I had a mini emergency, and now I basically have a new Ehiem 2217. Fish are all ok (I think, will check them when I get home from work).
Also note: This emergency was all mainly my own fault, Ehiem's are excellent filters, Which I have had running non-stop for about 4 years now.
Let me explain the history of my Ehiem;
About 2.5 years ago my original impeller was really rattlely, so I checked it and found that the impeller magnet was loose, so I got a replacement.
Move forward to about 3 months ago, the filter had stopped again, and I found that the latest impeller's magnet was split down its seam, completely broken.
So I replaced the broken one with my old rattlely one which was fine and let that run for a about a 2 months while I bought another.
Now I only clear/clean my cannister filter about once every 3 months I waited a little.
Forward onto about 1 weeks ago, when I needed to clear/clean my filter, I finally replaced the rattlely impeller with the new one.
As I replaced the impeller I pull all the guts out and cleaned the gooey buildup you get of brown muck around the pump head.
I then put the head back together and placed the impeller and connected it all back together. Attached the filter to my tank and got it going again. all good.
Then I was due to do another WC and I noticed that the tank was a little cloudy and there was not much water current.... "Oh my! the filter has stopped again, ok I can sort that out". As I opened up the filter checked the impeller, I noticed it was a little tight, then I noticed that there was a tiny bit of steam as I plucked it out, I then noticed the wall next to where the impeller sits was warped. "Oh no, looks like the heat of the engine with the seized impeller have melted the casing... not good". I then notice a little rubber nipple sitting on my filter media at the top of the cannister filter. It dawns one me... the shaft that holds the impeller central to the impeller was missing a rubber bit and due to missing it I had basically melted my pump head 
. "Ok, I'll get my other mini-filter, chuck it in the tank and deal with it tomorrow morning".
Next day (today) I drive over to Aquotix and try to buy a pump head, I find out that you can't get a pumphead as a spare part, you have to basically get a whole new filter. So I decided, well it's 4 years old, which is not bad, so I just bought a new ehiem (minus filter media), I then took it home and put the new pumphead onto my existing filter and got it going again.
My PSA to everyone: Ensure that when cleaning and putting your Filter together again that every piece is in it's correct spot as it may be a costly error ($243) and you may lose all your fish.
Tonight, As I have a new filter, I am going to change over all my pipes, filter, etc...
And also now I have a spare, which I probably sell parts of it to you guys.
cheap as chips but when you do a filter clean at 10pm and split or lose O-ring you'll be mad as hell cause shops dont open for at least 10-11 hours 
