I have another kit ready to go on so I decided to rehydrate the yeast following the instructions below to save 24 hours and bin it if it doesn't work, I poured it in at 9 last night and its putting a single bubble through the blow off tube every second this moring, my fingers are crossed.
I always rehydrate my yeast now. Gives a better brew in my honest opinion, no matter what you are brewing. The sinking of it in my last wort was rather worrying but it kicked off more than fine at 23C and 7 hours in