11
e) Remove burner closest to thermocouple for clear access to thermocouple nut.
f) Undo thermocouple nut at gas control tap.
g) Remove thermocouple.
h) Replace in reverse order.
3.5
Oven piezo Unit Removal
a) Open bottom front panel
b) Remove fixings that secure piezo unit bracket to base plate. Partly withdraw piezo unit and pull
igniter lead off.
c) Remove existing piezo unit from fixing bracket and fit replacement.
d) Attach igniter lead to replacement piezo before positioning.
e) Replace panel in reverse order.
3.6
Removal of Oven Spark Electrode
a) Open bottom front panel.
b) Remove thermocouple. See Section 3.4.3
c) Undo nut that secures electrode lead.
d) Undo gland nut and withdraw electrode.
e) Replace in reverse order and ensure thermocouple head is correctly positioned as detailed in
Section 3.4.3. The electrode conductor terminal should be clear of any adjacent metal parts.
3.7
Thermostat
3.7.1 Oven Control Thermostat
a) Remove vertical control panel and RH outer panel. (See Sections 3.2.3 and 3.2.1)
b) Undo inlet and outlet pipes compression nuts.
c) Remove fixings that secure right-angled bracket to Z bracket.
d) Open oven door and release phial by removing clips which secure it to roof baffle.
e) Gently pull phial and capillary tube through oven side hole and withdraw thermostat.
f) Remove right-angled bracket from existing thermostat and fit it to replacement.
g) Replace all parts in reverse order and check gas joints for tightness.
3.7.2 To Check and Adjust the Thermostat
a) Remove control panel as detailed in Section 3.2.3.
b) Replace knob and turn to 200ºC position. This should be
the temperature at this setting.
c) Place a temperature measuring device at geometric
centre of oven and light oven.
d) Allow oven to heat up for 30 minutes. Observe
temperature is steady. Compare value obtained with
required value of 200ºC.
Example
– Oven at 190ºC
Action
Turn knob to a higher setting until a temperature of 200ºC
±5ºC is obtained. Pull knob off without rotating spindle. Undo
fixings on adjusting flange at spindle base. Replace knob
and turn it back to 200ºC setting. Remove knob and tighten
adjusting flange fixings. Check temperature remains steady
at new setting for 200ºC.
Reverse action if oven temperature is above or below 200º.
e) Turn thermostat to lowest setting and adjust bypass
screw to achieve flame cone length of approximately
5mm. Check flame stability as detailed in Section 1.12.
