5
Adjustment on the PCB :
- P3 : potentiometer TAC (Temporisation Anti Cycle)
may now be adjusted between 30 seconds and 3
minutes (see detail) (factory set at 3 minutes).
- JP3 : the spade connector allows the gas rate to be
reduced to 1/3 performance by positionning
spade across pins as shown
A
Full performance across pins as shown
B.(factory
set)
After completling adjustments replace rubber cover and
refit outer casing
ADJUSTMENTS ON CONTROL PCB
ROUTINE SERVICING
To ensure continued efficient operation of
the appliance, it is recommended that it is
checked and serviced as necessary at
regular intervals. The frequency of servic-
ing will depend upon the particular instal-
lation condition and usage, but in general,
once a year should be adequate.
It is the law that any service work must be
carried out by a competent person such
as your local Chaffoteaux Service Centre,
British Gas or other CORGI registered
personnel in accordance with the current
Gas Safety (Installation and Use)
Regulations.
The service schedule should include
the following operations:
- Check the pressure in the system.
- Check the correct operation of the
appliance.
- Check the correct operation of the gas
controls.
- Check the functions of the safety con-
trols.
- Check combustion chamber insulation
panels for damage.
- Clean the burner.
- Clean the heat exchanger.
- Check the burner manifold injectors.
- Clean gas and water filters.
- Check expansion vessel charge pres-
sure.
- Clean and check operation of safety
valve.
Additional Procedures that may be
necessary:
- Check burner pressure and gas flow
rates.
- Check that the fan blades are clean.
- Check, clean and replace components as
necessary.
- Carry out combustion test utilising the test
points in the flue turret.
SUGGESTED SEQUENCE for SERVIC-
ING
Before disconnecting or removing any
parts, isolate the gas and electricity sup-
plies. Ensure that the appliance is cool.
(for detail please see section on Parts
Removal and Replacement)
Preliminary Checks
- Remove outer case
- Check the system pressure is at least
0.8 bar cold
- Check operation of solenoids.
- Check that the burner is extinguished fully
when solenoids are closed in both DHW
and C/H modes.
- Test ionisation functions and check that
lockout occurs by turning off gas tap.
Temperature regulation for both C/H and
DHW circuits are controlled by 2 thermis-
tors. The C/H knob allows the adjustment
of temperature between 35 and 85°C. The
DHW temperature is limited to 60°C. DHW
and C/H thermistors are identical and
interchangeable.
Resistance value are
-5000
Ω
at 25
°C
-2631
Ω
at
40°C
-620
Ω
at
80°C
-255
Ω
at
110°C
REGULATION
The air flow rate is detected by a pressure
differential created by a venturi located in
the flue duct.
ON threshold
∆
P > 130 Pa
OFF threshold
∆
P < 100 Pa
AIR PRESSURE SWITCH
C
10
C
10
C
11
C
11
C
38
C
38
F1
F1
F1A
F1A
J1J1
J2J2
J5 J5
MV1 MV
1
R67
R67
R72
R72
R73
R73
R
75
R
75
R
76
R
76
R85
R85
1
2
H
O
R
N
L
T
H
E
R
M
O
S
T
A
T
N
L
J
9
J
1
0
J
1
1
T
A
2
4
V
2
3
0
V
P3
(P3-P4-P5)
mini
maxi
Detail
P3
P3
1/3
3/3
P3
P3
1/3
3/3
P3
JP3
A
B
Summary of Contents for Calydra Comfort 100 Nat
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