I just installed the E3D V6 on a new Ultimaker 2 clone I am building. It's the 24V 1.75 universal model. I setup the included thermistor in the marlin firmware like the instructions detail (#define TEMP_SENSOR_0 5) and fire it up for the first time. When I connect the room temp is reading at 7 degrees. It's not that cold in here. So I tell it to heat to 200 degrees. It takes almost a minute before reading anything more than 7, but it does begin climbing steadily, though very slowly. When it reaches 200 I try to feed PLA through, it smokes and spits like an angry cat. It is obviously much hotter than 200. I have checked that the thermistor is seated correctly and reseated it with the same result. What have I done wrong? Any troubleshooting ideas?