-27-
Revision 7/F3527
©
Moffat Ltd, November 2004
No power to thermostat
Check voltage to terminal 2 on oven
thermostat. If there is no voltage then check
voltage through terminal 5 and one on hold
relay (behind control panel). If there is no
voltage to terminal 5 then check wiring. If
there is no voltage to terminal 1 then check
that the hold relay (fig 6.1.2) has no power at
relay coil terminal 7. If relay coil is not ener-
gised (ie no power at 7) and no power out of
terminal 1, then the relay is faulty—replace.
If relay is energised (ie power at 7) then
’Roast n Hold’ switch is on and unit is in hold
mode. Turn off ’Roast n Hold’ and recheck
operation.
NOTE:
There should be no voltage across
Figure 6.1.2
7
5
3
1
8
4
Relay
Gas valve faulty
The gas valve performs two functions:
- Providing regulation of gas pressure for
the burner,
- Opening and closing gas supply to the
main burner.
In all cases it must first be established that the
gas supply is on, that the manual isolating
valve in line with the gas valve on the
appliance is open, and that the supply
pressure is equal to or greater than the
required burner operating pressure (refer
specification section).
number 203926, using SIT ignition boxes,
check correct supply voltage across terminal
T10 (red phase wire), and terminal T12 (black
neutral wire) on ignition box.
In all cases, the measured voltage should
equal the supply voltage, ie 220-240 volts. If
not check wiring.
If voltage is ok, but no spark is generated,
check that all wiring at ignition box has good
connections.
Ensure that the ignition box has earth/ground
connection, and that appliance has earth/
ground at supply, and supply is earthed.
If all connections are ok, and no ignition
sequence operating, then ignition box is faulty
- replace.
If ignition box generates spark, but burner
doesn’t ignite, or if burner ignites but doesn’t
stay alight, firstly check correct electrode
assembly operation. Refer fault diagnosis
6.1.2 - Burner Ignition Spark Not Working.
If all checks are correct, but burner fails to
stay alight then ignition box is faulty - replace.
NOTE:
Correct flame sensing current can be
checked by inserting a multi-meter capable of
measuring micro-amps in series with flame
rectification rod connection to ignition box.
With power off, disconnect flame rectification
rod connection to ignition box and connect
multimeter between flame rectification rod
lead and ignition box terminal. Turn on power
and thermostat. With burner running a current
of no less than that specified below should be
read.
All Models
1.0 micro Amps
If no current reading, or less than specified,
re-check electrode settings, gas pressure, gas
type etc, and if still not correct, ignition box
requires replacement.
To determine if valve solenoids are operating
correctly, attach a pressure gauge to the
burner pressure test point after the gas valve,
and turn thermostat on. Check gas pressure.
If pressure is not correct for the appliance
specifications, remove the regulator cap on
the gas valve, and adjust the regulator spring
to increase or decrease the pressure. If the
pressure is unable to be adjusted, remove
regulator spring and check for correct type:
LPG/Propane
Blue spring
Natural
Gas
Green
spring
If the regulator spring and supply pressure are
correct, but the burner pressure is still
incorrect, check the gas valve solenoid
operation. With thermostat turned on check
voltage at connections to the gas valve.
110 volt models should have 24 volt ac supply
on both coils.
220-240 volt models should have 220-240
volts.
If voltage is correct when thermostat is on,
and gas valve is not opening then the valve is
faulty - replace. If voltage is incorrect, check
wiring and connections to ignition box and
refer to ignition box fault diagnosis.
