Eheim Jager Heater help

[Sobo's Reef]

This is my first time buying a Jager and I am completely confused by it. I set it to 78° but my tank reached 83°… apparently I'm not setting this right? Please help meeee

 

[Keithcorals]

Most heaters don't read the tank temp very well. What I and most people I know do is set the heater a little under what you want it and use the reading on your thermometer to slowly adjust the heater. In your case turn it down slightly and check the thermometer in an hour or two if it needs to go down more then adjust it a little more. I've owned a lot of heaters over the years and maybe one or two ever read the temp it actually was heating the tank to.

 

[Sobo's Reef]

Alright. Its odd tho, brand new heater, only a 16g tank. You'd think it'd be on the money. But a 5° difference??? That's insane. I almost cooked my RBTA

 

[Keithcorals]

Good thing you caught it in time. I've had enough heaters that I'm more surprised when they read the right temp at this point. I'm getting g a new heater in the next day or two I'll try and remember to post what it reads and what it heats the tank to. I can tell you the two heater I have now don't read the right temp. The new one will be plugged into a apex controller but I'll test it with it's thermostat first just to see what it does.

 

[Sobo's Reef]

Yeah my heater for my other tank will definitely be controlled by an apex. I'll hook the heater back up and set it to 75° and see what it comes out tk