38
4000123924-2
18 Fault Finding
COMPONENT
NORMAL MEASURE
CHECK
Gas control valve
Under demand during ignition sparks:
If 0 Volt:
the gas control valve
Resistance of coil 116
24V dc for 1 to 2 seconds, then
is not faulty.
12Vdc (constant) at the gas control
If 24 Volts and then 12 Volts
valve electrical connection.
but no gas at the burner:
Check if the gas control valve is
stuck. If not, check the
adjustment valve.
Adjustment valve
Close the gas inlet:
If the valve does not move:
(step motor)
Dismantle the step motor (screw not
Check the connections at both
sealed in). Trigger a demand and check
motor and control board (PCB).
that the valve opens during the ignition.
Change the motor. Replace the
control board (PCB).
(F30E/F35E Only)
Three way valve.
When heating is on:
If voltages are different:
Electrical supply to motor
230V ac between 1 and 2 of the motor.
Connections.
0 between 1 and 3.
About 25V ac to 35V ac between 2 and 3.
Control board (PCB).
9.6k between 1 and 2.
When hot water is on:
Three way valve lead.
9.6k between 1 and 3.
230V ac between 2 and 3 of the motor.
3 2 1
(1, 2 and 3 marked on
About 25V ac to 35V ac between 1 and 2.
the motor).
Thrust action of the motor.
Unfasten the clip (YES, no risk of water
If electrical supply is OK.
(remove gas control valve
leak), pull out the motor and leave it
but the motor axle does not move
before testing)
plugged in.
Replace the motor, or replace
When hot water is on:
the spindle should
the control board (PCB).
pull in.
When heating is on :
the spindle
should push out.
(F30E/F35E Only)
Domestic water flow
To test:
Use a new detector and
connect it electrically in place of
the faulty one . Blow through to
simulate a demand for water.
COMPONENT TESTING DATA
TYPE OF FAULT
CHECK
No display on control panel
• 230V supply
• PCB fuse
• Connection between PCBs
No domestic hot water
(F30E/F35E Only)
• Loose connections on control board (PCB)
No central heating
• Connections on air pressure switch (electrical or tubes)
(Red flashing warning light and flashing
disconnected
fault code in display)
• Faulty control or interface board (PCB's)
• Water pressure, flashing pressure
• Shortage of air or gas
• Faulty temperature sensor
• Overheating
Summary of Contents for 41-920-45
Page 59: ...59 4000123924 2...
