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C
hec
k
and correct if necessary
1
. The mechanical set of the gas valve
(
C
O2 values - see instruction)
2. Flame sensing electrode and lead connections
3. Flame sensing electrode position
Flame current should be more than 0.
5
A
Replace
PC
B
Replace
PC
B
Y
ES
Y
ES
Replace flame sensing electrode
NO
C
hec
k
the gas supply pressure:
For Natural Gas greater than
1
0 -
11
mbar
H
J
Replace safety thermostat
Y
ES
NO
Overheat thermostat operated
or faulty, i.e. continuity across
thermostat terminals
Allow to cool.
C
ontinuity
across thermostat terminals
more than
1
.
5
ohm
I
K
L
Is there 230V at:
Motor 3-way valve
Replace diverter valve actuator
1
.
Y
ES
PC
B -
X
3 connector terminals
5
& 6 central heating mode
5
&
7
domestic hot water mode
Replace
PC
B
2.
NO
C
hange pump supply cable
Y
ES
Fan connections correct at fan.
PC
B -
X
40
1
connector terminals
5
,6,
7
&
8
1
.
Y
ES
Replace fan
Temperature sensors faulty.
C
old resistance approximately
1
0
k
@ 2
5
°
C
(
C
H sensor)
20
k
@ 2
5
°
C
(Flue sensor)
(resistance reduces with increase in temp.)
NO
Replace sensor
Y
ES
If pump is running the heat exchanger could
be obstructed
Replace heat exchanger
1
.
2.
1
.
2.
1
.
5
2
© Baxi Heating UK Ltd 2015