"Daniel Morrow" wrote in message
...
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Bottom posted.

- --
You can find my public key at https://keyserver1.pgp.com
"NetMax" wrote in message
.. .
snip
My experience last night was that after noticing reduced water
flow
with my fluval msf 404 I unplugged it and plugged it back in and
noticed no water flow at all. Then I took the impeller well cover
off
and discovered the ceramic shaft sticking to the cover instead
of
staying in the impeller well. So I corrected it by removing the
ceramic shaft from the cover and inserted it back into the tiny
hole
in the bottom of the impeller well - and now it seems to be
working
perfectly. I just thought I would share my experience with these
things too. Thank goodness they are as reliable as they are
(canister
filters). Good luck and later!



When installed, I think the 404 shaft is in both the well cover and
a
black rubber washer at the other end. Which end it sticks to
during
disassembly is not material to its operation. Your re-installing
it
probably dislodged any mulm which was preventing the re-start.
jmo.
--
www.NetMax.tk



Interesting point netmax. I don't want to be picky but the hole in my
fluval impeller cover goes all of the way through it, so conceivably
gravity could easily pull the ceramic shaft down to the filter
chamber cover, probably removing the ceramic shaft most of the way
out. The only 2 things keeping my impeller in the impeller chamber is
1: the rubber hole now gripping the ceramic shaft, and 2: I lay my
fluval on it's side because the tank it filters is so low to the
ground and it doesn't hurt any, so gravity works differently for my
setup. Mulm in the impeller chamber can definitely be an issue at
times. The fluvals have self flushing impeller wells which probably
contribute to the fact that I can get away with not cleaning the
fluval often, but apparently mulm can definitely make hagen
powerheads unreliable at power on (start up). If the power goes out
and back on, occasionally the hagen powerheads will stick and do
nothing if they aren't kept clean, and there is a possibility that
cleaning it might not be enough (I don't know yet - still observing
my cleanings). Good luck and later!


being picky, no worries ). I'm still learning, and if hole in the
impeller cover goes all the way through, then you definitely have a
point. I'm going to have to take a closer look at this next time I have
one apart. The Fluval internals seemed to do this a lot to me (impeller
shaft sliding down), but I never had complaints about it.

The situation of not starting after a power interruption is not unique to
Hagen. It's more of a characteristic of magnetic impellers. The force
required to spin them is much smaller than the force required to start
them, so a bit of resistance from debris can cause them to not start.
Ironically, I think this is partly by design as they made the motors
smaller (cheaper, less heat generated, less electricity consumed). When
magnetic impellers were invented (I was in the hobby then, as many others
here) they were more powerful, so they rarely didn't restart from debris,
but they often didn't restart because of alignment. Instead of a well,
they used a platter, and the slightest misalignment would magnify itself
and wear the blades down from rubbing. When they lost power, they would
throw themselves over to a side so far as to not restart again. I
probably still have a box of impeller blades which have all been slightly
modified for balance. We are relatively spoiled today ;~).
--
www.NetMax.tk