When boiler or cooker thermostat is calling for heat, 230V
is supplied to terminal 1 of either burner control box and
the air pressure switch checked to ensure that it is in the
‘no-air position’.
Providing this check is satisfactory, after a short delay,
the burner fan will run (supplied from terminal 8).
The combustion air supplied by the fan will be detected
by the air pressure switch.
If this is also found to be satisfactory, after a delay 10-15
seconds of the fan pre-purging, the ignition device is
energised (supplied from terminal 7), at the same time
the twin gas valve solenoids are energised (supplied from
terminal 4).
Providing the start gas flame is established within 3
seconds and detected by the flame detection probe
(connected to terminal 12), the burner will run.
The gas valves are a two stage design and although both
solenoids open at the same time a low start facility
initially operates and the gas will run at full rate after
approximately 8 seconds.
SEE FIG. 39
Checks to ensure electrical safety should be carried out
by a competent person.
Check gas cock is in the on position.
Switch on the Electricity
Set the boiler burner time clock switch to continuous and
turn the boiler thermostat to maximum. The boiler burner
should run on pre-purge for 10 to 15 seconds, the burner
should then ignite.
Until all the air from the gas burner is purged out the
boiler may go to lock-out.
This will be shown by the burner stopping and the
illumination of the signal light in the reset button of the
control box, In this event,
wait at least one minute
, then
press the re-set button to restart.
Commissioning Instructions
30
ELECTRICAL CHECK
BURNER CONTROL
BOX OPERATION
DESN 511121
FIG. 39
DESN 511122
