I just don't have any luck with these eheims. Had two 300 watt heaters get stuck on the on position and this third one...well the temperature is 82 but it's set at 73...REALLY???
I've heard good things about this brand...hopefully they're true...
You only have to calibrate if the temperature isn't what you set it to, right?
I did calibrate the third one and it was working fine for a few months and then the temperature kept rising and then it would steady. Sometimes it would fall and then steady. It's at a constant 82 right now but it's set at 73 as mentioned. There's also condensation in the glass...did a google search on it...some said it's a red flag, some said its fine but I'm not risking it.
The two that were stuck, I had in the tank 24 hours to see if it would need calibrating but the light wouldn't go off and and the temperature kept going up.
I set my heater at 80F but my filter temp sensor detected and showing my water temp consistent at 76F, as long it stay as 76F then I'm not worry about it