While you wait for answers, we may have found some information which could help you.
Success
Message
Oil not reaching burner?
How to increase air supply to Riello RDB Burner?
riello 40 starts, runs fine then stops. ?
Riello 40 Burner problem?
how can i mend my riello burner rdb1 483t50?
can you fix the pump on a riello40?
My Riello 40 loses it prime ?
Fan Cage Making noise on a Riello 40 FS?
Bleed a boiler?
Burner not working ?
Bleeding it after oil ran out?
My riello burner lights for about 12sec and then locks out?