FR 553 then BA 839 at Dublin
Manchester → Dublin → London Heathrow
Timetable, Dublin time
21:25FR 553 from Manchester at the gate
20:40BA 839 to London Heathrow leaves the gate
23 h 15 apart on the timetable, overnight
BA 839 leaves 23 h 15 after FR 553 arrives on the timetable: more than half a day, so not a connection we count.