Rapid Fermentation Problem

[The Epworth Brewer]

Never had this problem before. Post boil I am using a copper coil wort cooler and leaving the wort in the boiler to ferment. Some brews are fully fermented within 48 hours, and none are taking more than 72 hours.
The problem is there isn't any life left in the yeast for secondary. I recently switched to a 50L Stainless set up and everything works well except this issue. I've tried spooning some yeast over from the boiler to aid secondary and it has helped, but not enough. On one brew, I ran the wort off into the SS mash tun in case the protofloc/trub in the boiler was the cause, but that didn't make any difference. If I transfer to a secondary fermenter after primary has finished there is hardly any yeast present when the secondary is emptied.I am baffled and just want to return to normal 4 - 7 day steady fermentation. I am using S04, as I have done for years.
Any suggestions what's causing this ?

[f00b4r]

I’m slightly confused as to what the issue is. I get that you are fermenting in the boiler (after chilling) but what are you hoping to achieve by moving it to secondary? Surely the point is moving to secondary in your case would be to just leave bright beer after a certain time (or maybe rack onto an adjunct)? Even if you do not see much yeast dropping out (it may have done in primary) it isn’t something to be worried about, there should be more than enough in suspension to carbonate if you are naturally priming.
Is there any reason you ferment in the boiler?

[The Epworth Brewer]

I use the boiler to ferment purely for convenience as I don't have a fermenting vessel, except a plastic one with 4" screw cap and airlock. Normally, after letting it stand in a secondary for 24-48 hours before racking off to barrel I am left with a nice clean film of good yeast at the bottom of the secondary, which I re-use. Following the same process now, there isn't enough yeast at the bottom of the secondary to fill a thimble.

[orlando]

What's the SG and FG? What temperature are you fermenting at? You don't need a secondary. There is always enough yeast to carbonate a Beer in recently fermented wort, so there must be something else going on here

[f00b4r]

So the issue is that you are not getting enough yeast in your secondary vessel to harvest for repitching?
If so then it might be that your processes are getting tighter so that your ferments are quicker and almost all the yeast is dropping out in your primary, if so it is not a bad problem to have and you might just have to either buy another fermenter or use your current secondary vessel and forget using a secondary.
I am not sure why it would occur when you used your SS mash tun to ferment in though. How many times have you been repitching that yeast? Orlando's has asked about OG/FG, are these changing from what you usually get in similar brews?

[Meatymc]

Transferring to secodary is surely to avoid large amounts of slurry? I tfr to secondary to dry hop with little sediment other than some hop fallout when transferring again to bottling bucket. If I want to capture yeast I use IPA's method - drawing off a PET bottles worth around day 3 of fermentation.