5
Fault Finding
20
Blue Seal Evolution Series Gas Convection Ranges
© Copyright Moffat Ltd. 21 June 2016
Amendment 13
5.2 Fault Diagnosis
Short in high tension lead
If repeated sparking of the piezo shows intermittent sparking at
the electrode, the lead should be traced to find where the short
is occurring. This can normally be visually seen as the spark
arcs.
If the lead is shorting, replace the HT Lead, as the electrical
insulation strength of the lead may have deteriorated.
If the spark arc can be seen at the electrode insulator at the
pilot burner instead of at the electrode tip, the insulator
probably has a fracture and should be replaced.
Piezo ignitor faulty
If no spark at all can be generated, remove piezo ignitor and
hold close to the hob body, depress piezo ignitor and if a spark
cannot be generated to hob body the piezo ignitor is faulty and
should be replaced.
NOTE:
If piezo ignition fails, the pilot can be lit manually
until the piezo circuit is repaired. A standard
taper torch or matches / lighter can be used for
manual back-up ignition.
5.2.1 Pilot goes out when Pilot Knob is
released
5.2.2 Piezo Ignitor not Sparking
Pilot flame too small
If pilot can be lit but the flame is too small to impinge on the
thermocouple, check the gas pressure. If satis, remove pilot
injector from pilot burner and check for blockages and / or
correct size injector.
Thermocouple faulty
Inspect thermocouple for build-up of carbon or food deposits on
the tip. Clean off any deposits, taking care not to scratch off
the aluminium coating on the thermocouple.
Check that the thermocouple tip is in the flame zone of the pilot
burner. When the burner is lit, the flame should impinge on the
top 5mm of the thermocouple tip.
NOTE:
The thermocouple should not touch the burner.
Check thermocouple connection to the gas control valve is firm
(loose connections will cause resistance in millivolt circuit and
result in pilot outage).
If connection is satis, disconnect thermocouple from the gas
control, light the pilot and whilst holding the control knob in,
measure voltage between the thermocouple internal wire and
earth (e.g. the body of the gas control). This should read
approximately 30mV. If this reading is less than 10mV, the
thermocouple is faulty - replace the thermocouple.
Gas magnet faulty
If thermocouple milli-voltage is above 10mV, and the pilot still
will not hold, the gas magnet is faulty - replace the gas magnet.
Figure 5.2.1
Tip
Internal Wire
Содержание Evolution Series
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