Which coil heads are you using. I have the H Plus and have not had any problem running it in SS Temp Control Mode. Well, let me take that back a little. I did have a problem with the original coil, but found out that when turning the juice flow control it would somehow loosen the coil head a little. Once I tightened it down, no more issues. I have run it on the RX200, Cuboid and Vaporflask Stout (all have basically the same Joyetech board). Also, make sure you have done the update on the RX. The first update was almost entirely related to TC with SS. Best of luck!!!