Is this heater safe?

If you can take it back. Do so. They are lousy heaters.

I have to disagree on this and disagree very strongly, I own a total of 22 of these heaters, most of which have seen over 5 years of service, some as much as 12. I have yet to have one fail or cause me a problem, the only one I ever had crack was left turned on when I drained the water it was in, and it didn't explode, only cracked slightly. I have one of my oldest 150 watts that the indicator light burned out on but it still holds the tank temp perfectly year round, despite the fact that you can't see when it is on or off. Although if I ever do have a problem I will switch to one of the more expensive heaters, I simply don't have any reason to change brands. If all of the products I used preformed as reliably as my visi-therms, I'd be a very happy person. IMO and IME you made a good choice with the visitherm deluxe. I doubt you will be dissapointed.
 
Visotherm also used to be made by someone else. Perhaps the new ones aren't as good as the old ones? I have a couple old Visa-therms and they work well, but I have not tried the new Marineland ones.

I know the store I work at gets a lot of them back as well though, so I generally recommend the Guardian, although at home I use Ebos or titanium. (I'd recomend those if we sold 'em, but alas, we don't)
 
Several (I think six) of mine are new, and they are doing great although I don't beleive ashort term test says much. I also think very highly of a lot of marineland products, and would endorse them at any time.
 
Yes, I too have also been very pleased with everything I have bought from Marineland (I recommend them to everyone). Of course I'll keep an eye on my heater anyway since I have only had it for a few months, but so far, so good.
 
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