Core UDC-30 Is my fan not working?

[jamiekerr14]

Hey guys, Long story short, I had a UDC-20 for about a year and worked great. And recently sold the 20 and got the 30. Im a bit confused about the fan. As my 20-Fan would nearly always come on, but the 30 hasn't come on as of yet. Im just discharging my newish Life RX pack.. and just felt the unit.. and its reasonably warm. Just wondering if there is a certain temp the 30 gets too before the fan comes on.. of if mine is broke? Tried some searching but nothing useful was found any ideas? P.S. Its being done by wall charger not 12v batt.. if that makes any difference..d