Cannot switch from Tank to Bags (2012 P&P)

[bjames]

Rear starboard P&P valve will not switch to bags. All i get is a N/C indicator. Service supposably fixed this and said there was something cloggin the valve, but for it to happen after the second use to the same valve has me suspicious that maybe the valve is faulty.

Is there a way I can trouble shoot this myself? Where is this valve and is it easy to flush it out (assuming something is caught inside?)