Aquarium Aqueon Submersible Heater 50 Watt

I believe this product may have a manufacturers defect. I ordered one from allpet.com and followed the instructions very carefully. set the temp and placed in the water - immediately bubbles started coming up from the top cap which i did not at first believe was a problem. after about an hour in the submerged water i noticed that water had collected at the bottom of the heater. i notified allpet and they immediately sent me a replacement no charge. then again yesterday i again followed the instructions with the new replacement but this time no bubbles came up. after an hour in the water i plugged in the heater and it worked like a champ. THEN, bubbles started coming up from the cap again! i had to turn off the entire circuit in my house to avoid being shocked (this is what they tell you to do in the instructions). im pretty annoyed at this point - perhaps this heater is NOT fully submersible. i am going to see if i can get another replacement from allpet to see if the heater works without being fully submerged. thus far quite a waste of time and energy.

NOTE: AllPet has responded very quickly to this issue thus far and is in no way responsible for this defect as far as i can tell. i will post the results of the 3rd heater once i test it.

My only complaint is that the heat from the unit has caused dried burnt on crusty stuff, I am quessing the aquarium sludge, as I keep 12 pretty large Koi in my aquarium after losing my pond.Heats too well almost, on the lowest setting it keeps the water about 75, the koi seem to be thriving though as they eat more often and have grown inches in the past 2 months.
Great service..will use again..

I use this for my 100 gallon tank and I couldn't be happier. I have been using it for about the last year and it has worked perfectly since day one. It is really simple to hook up and use. I would highly recommend this product.