While you wait for answers, we may have found some information which could help you.
Click here for Boiler Keeps Cutting Outriello rd 3 boiler burner unit?
Lost allen screw when bleeding boiler?
my riello oil burner just makes abuzzing sound?
My riello boiler won't start after replacing the water pump?
Biasi sg3 Riello 40 burner constantly firing?
Riello Burner Motor Sound?