Power +8000 hot air/soldering station (+YH850V6 based air controller)

[neex]

Good evening everyone,
   I have also jumped on the cheap/cheerful hot air station bandwagon and had a question about the pump voltage control...  The unit I have is a Power 8000 which appears to share the same hot air controller as many other clones: YH850V6.  My question is that I was wondering if anyone else with a similar unit could confirm that the 3 gang pot for "AIR" is actually wired with only two terms almost like a rheostat?  My pot appears to do very little in the way of controlling pump voltage.  The controller has inputs for both the grn and yel wire on the pot and they're marked "AIR VOL 1" (3 wires... RWB) and "AIR VOL 2" (2 wires... YG).  I believe that the pot up front is meant to vary the pump speed through the AIR VOL 1 circuit but I'm not sure if there's anything oddball to be concerned with here and was hoping someone might know.

Is the triac without the heatsink the regulator for pump voltage???



Thanks in advance.