DETAILS OF PROBLEM
The apparatus goes into "lock-out" with
the flame (red light on).
Fault restricted to flame control devi-
ce.
The apparatus goes into "lock-out", gas
flows out, but there is no flame (red light
on).Fault restricted to ignition circuit.
The apparatus goes into "lock-out",
gas flows out, but there is no flame (red
light on).
TWO-STAGE GAS BURNERS: TROUBLE-SHOOTING GUIDE
POSSIBLE CAUSE
1) Disturbance to ionization current from
ignition transformer.
2) Flame sensor (ionization probe) ineffi-
cient.
3) Flame sensor (ionization probe) position
incorrect.
4) Ionization probe or relative earth cable.
5) Electrical connection cut-off by flame
sensor.
6) Inefficient draught or fumes passage
blocked.
7) Flame disk or combustion heads dirty or
worn.
8) Equipment fault.
9) No ionization.
1) Fault in ignition circuit.
2) Ignition transformer cable discharges to
earth.
3) Ignition transformer cable discon-
nected.
4) Ignition transformer faulty.
5) The distance between electrode and
earth is incorrect.
6) Isolator dirty, so electrode discharges to
earth.
1) air/gas ratio incorrect.
2) Gas pipe has not been properly bled of
air (in the case of first ignition).
3) The gas pressure is insufficient or exces-
sive.
4) Air flow between disk and head too nar-
row.
40 / 71
0006081042_200806
SOLUTION
1) Invert the ignition transformer power
supply (230V side) and check using an
analog micro-ammeter.
2) Replace flame sensor.
3) Correct the position of the flame sensor,
and then check its efficiency by inserting
the analog micro-ammeter.
4) Check visually and using the instru-
ment.
5) Restore the connection.
6) Ensure that the boiler fumes passage
and chimney connection are free.
7) Visually check and replace, if neces-
sary.
8) Replace.
9) If the "earth" of the apparatus is not effi-
cient, do not check the ionization current.
Check the efficiency of the "earth" at the
terminal concerned of the apparatus 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 replace isolator and electro-
de.
1) Correct the air/gas ratio (there is proba-
bly too much air or very little gas).
2) Bleed the gas pipe again, taking great
care.
3) Check the maximum gas pressure value
at the time of ignition (use a water
pressure gauge, if possible).
4) Adjust the disk/head opening.