Quote Originally Posted by skinnee View Post
The only difference is the sticker and the impeller on the OP's, the pcb's are the same for all of the PMP-400's. I can swap impellers between the two, same size and the difference being the bottom piece of two molded pieces.

So we're left with stickers?
Well, there hasn't been a whole lot of impeller flashing going on is this thread (with the exception of the OP), so I can't speak for that. All I know is, if you have a blue impeller, it "should" be a 3.x. If it's multicolored (Blue and brown/red), it's supposed to be a 3.x5. The way Laing screws around with the DDC line, I'm starting to think pressure testing (whether it be dead head or manometer) is the only definitive way to tell what pump you got.