Eheim tru temp can't keep up.

[rvlcf]

I set up a reefer 450, 116 gallons, and purchased a new Eheim tru temp heater
250 watt. The heater is rated to work between 106 and 159 gallons. It can't get the temp over 70 degrees. I added a secondary small heater to get the temp to 80 degrees and when it reached 80 I unplugged it, hoping the Eheim would maintain it at 80. The temp fell back to 70 overnight. It has been on the whole time, with the orange light on.
Does anyone think i have a defective heater, or is the rating on this heater incorrect?
Thanks for your input.

 

[GimpyFin]

I have the same 250W Eheim jager on my 110 gallon (Roughly 130 gallon with sump volume.) Mine stays solid at the temp I set (77.) It may fluctuate a half degree here/there depending on temp in the house, but that's it. Sometimes, the Eheims do need to be re-calibrated as they are off a little from the factory, but if you can't get it to go over 70, it may just be defective.

 

[thegrun]

The general rule of thumb is to have between 4 and 5 watts per gallon, so despite the manufacturer's claim, I just don't see you having enough wattage. I would add a second heater. It's always a good idea to use two heaters each at half your total needed wattage so that when one goes bad (they all will eventually fail), you have more time to spot and correct the problem before your tank either overheats (they usually stick in the on position when they fail) or cools down too much.

 

[JohnnyHildo]

i use 2-250 watt eheim heaters in my 120g and it works perfectly. add in your other heater permanently and you're good to go.

 

[merlinpi]

looks defective to me. They do have a good customer support. Call them. I personally didn't have much with Eihem though and I switched to Fluval. The Eihem now heats my water change Brute container...

 

[rvlcf]

Called Marine Depot and they are sending a replacement. We'll see if it was defective,
or just doesn't have the chops to keep up!
Thank you for your responses, much appreciated.