Unit installation

After the controller issues a heat

demand, the following program

sequence will be run:

Phase Duration

01 Test for heat demand 1 s

02 Checking the idle state of the air pressure switch and the

fan

1 to 30 s

03 Fan ramps up to speed (a fault shutdown will be initiated

if the air pressure switch does not report within this time

that the air pressure has reached a defined range, or if

the fan does not reach its set speed)

1 to 30 s

04 Pre-purge I 5 s

05 Pre-purge II 1 s

06 Pre-purge III 30 s

07 Ignition setting (the burner control unit will enter a fault

state if the fan does not achieve its set speed)

1 to 30 s

08 Pre-ignition 2 s

09 Safety time, start (safety time A) (enabling the safety

valves at the start of safety time A, safety time, operation

< 1 s); (no gas pressure switch monitoring)

2 to 10 s

10 Stabilising the flame in the ignition position 20 to 60 s

11 Changing to the control mode (ramps to the set speed

selected at the control unit)

1 to 30 s

12 Operation (the system will be restarted after expiry of this

time)

max. 23:59 h

13 Burner run-on time max. 30 s

17 Post-purge 1 to 60 s

18 Restart blocking time 0 s

19 Gas shortage position max. 30 min

20 Standby

(a restart follows a heat demand and the system restarts

after expiry of this time)

max. 23:59 h

In the case of fault shutdown from phase 09:

21 Fan run-on before lockout 5 s

Burner control unit flow chart

(cont.)

5692 907 GB