Yes you can submerge them. I was told from the distributor that the
waterline mark had to be placed on the heater because otherwise they
did not meet some regulatory standard in the US. Same models are sold
worldwide without the waterline mark. Actually, at times, you see US
retailers selling the models intended for non-US market as "FULLY
SUBMERSIBLE EBO-JAGGER!!!" just because they are missing some ink on
the glass

At least that's what I was told, I have 3 of them and keep them
submerged without problems, mine are all vertical however my LFS keeps
them all horizontal in their display tanks. As far as accuracy, they
are better than most on the market (of similar design that is). And
you really shouldn't depend 100% on what the dial says when setting a
heater, that's what thermometers are for. Once it's set, it stays
stable so you can remove the thermometer and just check temp from time
to time.

Hope that helps
Giancarlo Podio


"Tom B." wrote in message ...
I just purchased an Ebo-jager 100W heater for my 10g (I know a 50w would be
better for 10g but it's really a backup heater for my primary tank, a 20g)
tank thinking it was a fully submersible heater. when I got it though it
doesn't say anything specifically about being submersible and it has a water
line near the top of the heater. Is it submersible or not?

Also, what is a better way to mount a heater, horizontally or vertically? I
had the impression the horizontal was better but the instructions that came
with my other heater (ViaAqua 100w Titanium tube) say not to put it that
way.