To increase superheat on a TXV system, you should turn the spring:

In a thermal expansion valve (TXV) system, superheat is the temperature of the refrigerant vapor above its saturation temperature at a given pressure. Adjusting the spring tension in the TXV directly influences the flow of refrigerant into the evaporator and subsequently affects the superheat level.

When the spring is turned clockwise, it increases the tension, which in turn raises the pressure on the diaphragm. This leads to a reduction in the flow of refrigerant entering the evaporator. As less refrigerant enters the evaporator, the refrigerant that does enter has more time to absorb heat, potentially raising the superheat. Essentially, by increasing the spring tension, you can achieve a higher superheat, ensuring that the system operates efficiently and prevents flooding of the evaporator with liquid refrigerant, which could cause compressor damage.

In contrast, adjusting the spring in other directions or randomly would not provide a controlled approach to managing superheat and could lead to erratic system behavior, flooding, or inefficient performance. Thus, adjusting the spring tension in a clockwise direction is the precise method to effectively increase superheat in a TXV system.