HOW TO FIND THE CAUSES OF IMPROPER OPERATION OF TWO-STAGE GAS BURNERS
AND HOW TO RECTIFY THEM
PROBLEM
The equipment goes into "lock-out" with
t h e f l a m e ( r e d l i g h t o n ) . M a l -
functioning is due to the flame
control device.
The equipment goes into "lock-out",
gas flows out, but there is no flame
(red light on).
F a u l t
i n
i g n i t i o n
circuit.
The equipment goes into "lock-out",
gas flows out, but there is no flame
(red light on)
POSSIBLE CAUSE
1) Disturbance to ionisation current from
ignition transformer.
2) Inefficient flame sensor (ionisation
probe).
3) Flame sensor (ionisation probe) position
incorrect.
4) Ionisation probe or relative earth cable.
5) Flame sensor electrical connection
cut-off.
6) Inefficient draught or fumes passage
blocked.
7) Flame disk or combustion head dirty
or worn.
8) Faulty equipment.
9) No ionisation.
1) Fault in ignition circuit.
2) Ignition transformer cable discharges
to earth.
3) Ignition transformer cable discon-
nected.
4) Faulty ignition transformer.
5) The distance between electrode and
earth is incorrect.
6) Isolator dirty, therefore the electrode
discharges to earth
1) Air/gas ratio incorrect.
2) Gas piping has not been properly bled
of air (in the case of first ignition).
3) The gas pressure is insufficient or
excessive.
4) Air passage between disk and head
too narrow.
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0006081531_201203
SOLUTION
1) Invert the ignition transformer power
supply (230V side) and check using an
analogue micro-ammeter.
2) Replace the flame sensor
3) Correct the position of the flame sensor,
and then check its efficiency by connect-
ing the analogue micro-ammeter.
4) Check visually and using the instrument.
5) Restore the connection.
6) Ensure that the boiler fumes passage
and chimney connection are free.
7) Visually check and replace, if necessary.
8) Replace.
9) If the "earth" of the equipment is not
efficient, the ionisation current cannot
be checked. Check the efficiency of the
"earth" at the terminal concerned in the
equipment and at the "earth" connection
of the electric system.
1) Check the ignition transformer power
supply (230V) and high voltage circuit
(electrode to earth or isolator broken
under locking terminal).
2) Replace.
3) Connect.
4) Replace.
5) Position at the correct distance
6) Clean or change the isolator or electrode.
1) Correct the air/gas ratio (there
is probably too much air or very
little gas)
2) Bleed the gas pipe again, taking
great care.
3) Check the gas pressure value at
the time of ignition (use a water
pressure gauge, if possible).
4) Adjust the disk/head opening.