I used S-04, I was thinking its a bit high as well, but it seems finished, im gonna take another reading tonight, and then tomorrow... But it was my first AG, so I may have got more unfermentables than expected...
Got my 41L pot in the post yesterday and picked up the fabric material etc for the bag at Spotlight. Alas Bunnings were doing a cleanup/stocktake on the BBQ area so I couldn't buy a 3-ring burner, but anyway, here's a recipe idea for my first AG using BIAB...
St Paddies Steadfast Stout v2.0 (based off my extract version, since it's very popular with the palate, and flatmates!)
4.2kg Pale Malt
350g Roasted Barley
250g Chocolate
150g Crystal 70L
50g Black Patent
23g Pacific Gem @ 60 mins
Safale S-05
OG: 1.047 | IBU: 34
Upped the roasted barley by a fraction, added a little black patent. Dropped the 45/25 min additions, as I didn't like the flavouring present.
I was thinking 14 initially, but it appears to have stopped, I put the heater belt on it to see if it moves, so ill check it tonight... It has been fermenting now for about 9-10 days, so for an ale that should be plenty of time...
mashed in at 66 degrees, it had dropped about 3-4 degrees after an hour so I brought it back up to 65 and left for another 30 mins...
S-04 is sposed to be quick, it was fermenting like crazy for a good few days and then just sorta stopped, I played with the heater belt over the last few days to bring it up to 20 and then to 22, then I took my first reading last night...
I also bottled a schwarzbier last night which started at 1052 and finished at 1017, I thought that was high as well, but the same reading over three days.. Using Saflager S-23 yeast for that one...
Sounds like you might need to tweak mash temps for your system.
A couple of degrees makes a huge difference to fermentability in my experience. I've had issues getting tiny beers like milds to attenuate at times - high percentage of crystal and other specialties - finishing around 1.016. I rebrew and drop mash even 2 degrees, they finish where they're meant to - 1.011.