General needs block of flats. All the smoke heads have been taken out of the flats and replaced solely with heat detectors. This was done to cut down on false alarms as the smoke heads were causing signals from cooking, aerosols, steam etc. Does BS 5839-6:2019 condone this? 

Ive suggested multisensor heads if the rationale was due to sensitive heads being activated. I’ve also highlighted that smoke logging will occur potentially before activation of the heat detectors. 

Depends what the detectors were there for - if part of a common system for full evacuate then heats is the normal provision because of the resultant false alarm risk which leads to vandalism and apathy to the alarm sounding - it would also be a Part 1 system. After all the system is not the for life safety of the flat of origin, that's what the local Part 6 systems to each flat are for.

If It's a weird system where one system is trying to be both the common system and local system (not unheard of and common in HMO's and some conversions) then smokes are a must and hush buttons or Cause & Effect programming be used to prevent site wide false alarms.
 

The purpose of a FRA is to what is required and needed in accordance with the fire safety order. Each flat requires a domestic part 6 smoke detector system and the common areas may require a part 1 smoke alarm with a heat detector located inside each flat adjacent to the front door so without a full survey it is impossible to ascertain what is required.