20
Concord CXS -
Installation & Servicing
Refit the electrical plugs and the dust and plastic covers.
Failure to follow this procedure may result in the correct burner
pressure being set
but
the 2 gas valve governors
not
working
correctly.
CXS 110 - 120 Boilers
The setting procedure must be done in 2 steps.
The location of the manifold pressure adjusters (1 & 2) on the
gas valves are shown below. Remove the dust cover and using
a screwdriver screw in the adjuster (1) on the LH gas valve nearly
fully.
Prise off the plastic cover on the High/Low solenoid (3) on the
RH valve and using a suitable spanner set the burner pressure
adjuster (4) to the value given in Table 8 below. Then unscrew
the adjuster (1) on the LH valve until the burner pressure falls
and then reset it to the value given in the Table 8.
Now set the Low burner pressure by unscrewing and removing
the lower electrical plug from the LH gas valve and the High/
Low plug from the RH gas valve. Using a screwdriver turn the
screw (6) within the spindle on the RH valve to set the burner
pressure to the value given in Table 8 below.
Refit the electrical plugs, the dust cover and the plastic cover.
Failure to follow this procedure may result in the burner pressure
being set
but
the 2 gas valve governors
not
working correctly.
Table 8 Manifold gas pressure settings
21 MANIFOLD GAS PRESSURE
INSTALLATION
INST
ALLA
TION
The manifold setting pressure must now be checked and
adjusted as necessary.
It is essential to set the High Pressure
first
Start the adjustment procedure with the system cold, on full load
and with all temperature controls set to maximum to avoid
thermostatic shutdown. Remove the screw in the manifold setting
pressure test point and connect a suitable gas pressure gauge.
Turn on the electrical supply to light the boiler and let it operate
for about 10 minutes to stabilise the burners. Check the pressure
and if it differs noticeably from that given in Table 1 for the
appropriate boiler size adjust it as follows:
CXS 40 - 90 Boilers.
Refer to Frame 20 illustration. (
Numbers in brackets in this 40-
90 section also refer to Frame 20)
.
The location of the manifold pressure adjuster (8) on the gas
valve is shown in Frame 20. Prise off the plastic cover on the
gas valve (9) and, using a suitable spanner, set the High burner
pressure adjuster (10) to the value given in Table 1.
Undo the screw retaining the electrical plug (11) on the High/
Low solenoid on the gas valve and pull it out.
Using a screwdriver turn the screw within the spindle to set the
Low burner pressure adjuster (12) to the value given in Table 1.
Refit the electrical plugs and the dust and plastic covers.
CXS 100 boilers
The setting procedure must be done in 2 steps. The location of
the manifold pressure adjusters (1 & 2) on the gas valve is shown
below. Undo the screw holding the lower electrical plug on the
LH gas valve and pull it off. Prise off the plastic cover on the
High/Low solenoid (3) on the RH valve and, using a suitable
spanner, set the burner pressure adjuster (4) to the value given
in Table 8. Refit the electrical plug and secure with the screw.
Remove the dust cover from the adjuster (1) on the LH gas
valve and set the pressure to the value given in Table 8.
Now set the Low burner pressure by unscrewing and removing
the lower electrical plug from the LH gas valve and High/Low
plug from the RH gas valve. Using a screwdriver, turn the screw
(6) within the spindle on the RH valve to set the Low burner
pressure to the value given in Table 8.
LEGEND
1.
Manifold pressure adjuster (LH valve).
2.
Manifold pressure adjuster (RH valve)
3.
Main gas inlet cock
9
7
3
4
6
5
7.
Left hand gas control valve.
8.
Right hand gas control valve.
9.
Manifold pressure test point
3
2
8
1
7
8
4.
High burner pressure adjuster (RH valve).
5.
High/low solenoid connector.
6.
Low burner pressure adjuster (RH valve).
At the end of the adjustment procedure ensure that all
covers are replaced, disconnect the gas pressure gauge
and replace the blanking screw in the manifold pressure
test point.
Boiler
RH valve
LH valve
Low rate
adjustment
and Final
pressure
pressure
adjustment
- mbar
- mbar
pressure
- mbar
CXS 100
11.0
11.5
4.1
CXS 110
12.3
11.8
4.3
CXS 120
12.5
12.0
4.5
