FR 815 then EI 166 at Dublin
Edinburgh → Dublin → London Heathrow
Timetable, Dublin time
20:25FR 815 from Edinburgh at the gate
13:00EI 166 to London Heathrow leaves the gate
16 h 35 apart on the timetable, overnight
EI 166 leaves 16 h 35 after FR 815 arrives on the timetable: more than half a day, so not a connection we count.