56
Response FF80
- Installation
86 Flame detection and mixture
Note.
When panels are removed for service, live parts are exposed so caution should be exercised when fault-finding.
FAULT FINDING
Foot Note:
POLARITY CHECKS
Use a multimeter (set to measure 230 V AC or more), connecting the black lead to a reliable
Earth
point (
not Neutral for this
particular test)
.
You should find 230 V on terminal L and zero (or a small reading) on terminal N.
N.B.
Some meters may trip residual current devices during this test.
Remove the fan.
Is the detection lead undamaged and attached
to the (single) detection electrode terminal at
the rear of the burner base ?
Check detection lead for continuity.
Check that the electrode is in the flame area
and within 12mm (± 1mm) of the burner at
closest point.
Rectify any fault.
Does the boiler now run ?
YES
Is this a new installation ?
Has any electrical work been done to the boiler
or the house wiring ?
YES
Check the polarity of the incoming mains to
the boiler (see footnote).
Is this correct ?
YES
Check the polarity of the mains input
to
PCB 37
when the fan starts.
Is this correct ?
Does the boiler now run ?
Remove the burner assembly.
Check the detection electrode visually for
damage / contamination / moisture.
If possible, check insulation resistance between
the electrode and earth with the lead
disconnected - this should be at least 100
Megohms.
Is it OK ?
NO
NO
YES
YES
NO
Check all connections on PCB 37.
Check for moisture on PCB 37.
If no fault found, check PCB 37 by substitution.
YES
EXIT
YES
YES
YES
NO
F
AUL
T FINDING
Boiler does not light, or lights briefly
at the
correct
burner pressure then
goes off, leaving LED 2 on PCB 37 lit
Check that the gas injector is of the correct size
(see Data Plate) and is unobstructed.
Is this correct ?