balboa m-series value pack reads Pr atstart up (no visible pressure switch),then when I press the jets button SL or 5L flashes. Please advise.

Pr = Priming - system assessing water presence - can take 5 minutes to go through start up on some models
SL = sleep or possible other programming mode
download a manual here http://www.spaparts.com.au/webcontent12.htm#

Thanks alacy.

I've installed a couple of these newer systems recently and I'll tell ya... I was about to pull my hair out - (what little I don't have!) - when the stinking thing did nothing on power up! Priming mode. Good grief go figure.

They need to change that to - (P)iss up a (R)ope mode while I wait here and do nothing, in the meantime, you're looking stupid and wondering why nothing's happening!

rotflmao! I love it, but it still makes no sense to me.

yep, certainly makes a tech look stupid waiting for the priming mode to finish - many also have straight lines after the Pr code which is still part of it.