Hi I have a worchester heat slave 18/25 and continually needs bleeding

[Declan123]

Hi I have a worchester heat slave 18/25 and continually needs bleeding of the Kero, runs all day when bled. when it cuts out on the stat it wont start again without bleeding

 

[John.g]

Is the tank higher than the oil pump?, what is the oil level?
Is it a one pipe system with the blanking bypass screw installed/ or a 2 pipe or a tiger loop?.
Has the flexible hose been replaced fairly recently?.