Here are two threads that talk about having thermal runaway problems on a MakerFarm printer -

http://3dprintboard.com/showthread.p...-ambient-temps - Here the problem was a bit too much print cooling fan airflow in at a cold ambient temperature tripping the hot end thermal runaway.

http://3dprintboard.com/showthread.php?10166-Thermal-Runaway-Protection-(Dual-Extruders) - Here the problem was the heated bed, but the OP didn't come back and say what he did to fix the problem. Like here, the thermal runaway problem showed up as soon as he enabled detection for it.