53
Response 80 / 100 / 120
- Installation
NO
FAULT FINDING
83
Power to PCB 41 but burner pressure incorrect or zero
Notes.
1. The burner pressure is not user-adjustable: it is regulated by the gas valve, according to the air flow generated by the fan and, on cold
ignition, should be slightly higher than the value quoted on the Data Plate. Long flues will cause a slightly lower burner pressure than
standard flues.
2.
Equilibrium fan differential pressures should be as detailed in Frame 45.
NO
Clear the blockage and take steps to
prevent recurrence
NO
Are air and flue ducts free from blockage ?
Check all items connected to PCB 41
for short circuits between Live and
Neutral, also between Live and Earth.
If none found, reconnect one by one
(gas valve last) until the faulty item is
found.
If no fault found or fuse blows with no
items connected, check PCB 41 by
substitution.
Is the appliance gas cock fully open ?
NO
NO
Is the gas supply pressure adequate at
the appliance inlet during an ignition
trial period (i.e. when LED 2 on PCB 41
goes off) ?
NO
YES
Contact the
gas
supplier
Is the supply pressure correct at the
gas meter ?
Rectify the fault and take steps to
prevent recurrence
NO
Is there Live on the brown lead of the gas
valve connector on PCB 41
during an
ignition trial period ?
Are both connectors correctly fitted to the
gas valve, with screws secured
but not
overtightened ?
Remove connectors. With mains OFF,
check continuity of leads from each socket
unit back to the corresponding terminals in
the control box. Are leads in good order ?
YES
YES
YES
YES
YES
YES
YES
YES
Determine the cause of
pressure loss (e.g. supply
pipe too small ?) and rectify
Check PCB 41 by substitution
Is the fuse good on PCB 41?
(LED3 lit confirms this)
Is the fan pressure sensing pipe correctly
connected, free from damage and
unobstructed by solid matter or moisture
?
F
AUL
T FINDING
Change lead assembly
Replace gas valve solenoids
Is burner pressure
correct ?
Return to main
menu
NO
YES
Replace gas valve
Summary of Contents for responce 100
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