thanks for all the feed back.. to answer a few.. I have fermented this yeast even higher..28c it can handle it.. wasnt by choice, but just happened to be that high and couldnt lower it.. but it turned out fine.. I normally ferment this s23 at room temp.. 22 to 24 c never have an issue.. you can do this with some yeast,, s23 is able to ferment this high.. Im using dry yeast, so you can train it to do what you like really,, but I will try and lower the temp to 20c ,, and see if there is any difference. as not all batches of yeast, dry or liquid will be 100% the same,, maybe I got a batch that couldnt handle the 24c temp??? possible!!
I changed the carbon filter today,, the old one was still working fine as there was no signs of chlorine even after passing 500 liters through it,, but changed it anyways as im not sure if this municipality uses chloramine,, maybe the old carbon filter was not removing chloramine if they do use it? so a new filter will maybe tell me something?
The yeast might be an issue,, but not sure.. I know lots of people using this yeast at higher than recommended temps and its never been an issue ? but who knows,, maybe its pushing the envelope for it..? 15c is the high end on the label, but weve pushed this yeast before for many years and not had issues.. so not sure why 3 bathes have now suddenly gone off? Im scratching my head on this one..
acid washed the stainless kettle today.. so no chance of bare metal ... checked PH again on water,, its 6.5 so will add some acid to the sparge water.. keep it down under 6
other than this.... im at a loss .. will keep you all posted cheers