@barcwik
If you're happy with controlling it through c-code without feedback then: (however I'd rather put the fan under thermostatic control. Maybe explicitly starting it and switching to thermostatic control once chamber temperature has been reached.)

-> heater ON -> Turn fan ON

M106 P2 S255 ;turn on chamber/fan2
M141 S50 ;turn on chamber heater
M149 ;optional wait for chamber temperature

-> Heater OFF -> Let fan ON for a delay then turn OFF

M141 S0 ;turn off chamber heater
G4 S10 ;wait 10 seconds
M106 P2 S0 ;turn off chamber/fan2

you'd also want to consider what happens when things don't go according to plan, and where to place the g-code

Huh, didn't intend to tag Sim234, but seems it does so if you qoute and delete the refrence in the post.