A ... B

Controlled operation with fuel oil

Change from single-fuel operation (oil) to simultaneous firing

B ... C

Preselection of simultaneous firing and gas valve leak test

C ... D

Gas fuel ignition sequence

Change from simultaneous firing to single-fuel operation (gas)

E ... F

Cut off fuel oil with blow-out of the oil gun

F ... G

Controlled operation with fuel gas

Change from single-fuel operation (gas) to simultaneous firing

G ... H

Preselection of simultaneous firing and enable atomization

H ... I

Oil burner ignition sequence

I ... J

Simultaneous firing active

Change from simultaneous firing to single-fuel operation (oil)

J ... K

Cut off fuel gas

K ... L

Controlled operation with fuel oil