Riello 2.2 rgb oil burner won’t start

[Nicjones]

Hello all
Our riello burner intermittently won’t ignite. However for some reason when you tap gently the oil pump it lights every time. Any help appreciated. Thank you

 

[exedon2]

Competent oil engineer required.
If it requires say a new pump you cannot set anything up without at least a pressure gauge and commission analysis equipment.