IDEAL Concord CXi 110 Installation & Servicing Manual page 22

25 ADJUSTING THE MANIFOLD PRESSURES - continued
After setting, allow the boiler to operate for 3 minutes to
stabilise then recheck the setting.
Note - CXi 180 only.
Do not adjust the middle valve, which is factory set.
7. Press the [0/1] button to turn the boiler off then:
a. disconnect the 'high' solenoid plug from the top valve.
b. CXi 180 only - disconnect one solenoid plug from the
middle gas valve.
c. Disconnect one solenoid plug from the bottom valve.
Turn the boiler on and set the low pressure to the value
given in Table 1, using the low rate adjustment screw
inside the spindle of the top valve.
26 OPERATING INSTRUCTIONS
The Concord CXi features direct burner ignition, high/low
burner operation and a microprocessor control system.
Upon a demand for heat, the controls open the low rate gas
valve and provide a rapid spark at the ignition electrode for up
to 10 seconds.
The burner will light and remain at low rate for approximately
3 minutes before proceeding to high rate, when the
microprocessor opens the remaining gas valve(s).
If the boiler fails to light, the gas valve is closed and there will
be a delay of 1 minute before the cycle is repeated. If, after 5
attempts, the burner has failed to light, the boiler will go to
lockout and
22
INSTALLATION
will be displayed on the screen.
8. Turn the appliance off and
reconnect all the solenoid plugs.
Do not overtighten the solenoid
plug fixing screws.
Refit the dust cover over the
adjustment screws and refit the
pressure test point screw. Check
for gas soundness.
9. Press [EXIT] to leave the
commissioning mode and return
to the main menu.
10. Press [EXIT] again to return to the
status displays.
When the boiler flow temperature reaches the thermostat set
point, the controls will turn the burner to low rate. If the flow
temperature continues to rise the burner will be turned off at 3
0
C above the set point. If, however, the temperature falls
below the set point whilst on low fire, the controls will
automatically turn the burner back up to maximum rate.
This system has the advantages of ensuring that the boiler
accurately maintains the set temperature (without the large
temperature swings that can be associated with on/off
boilers), prevents rapid or short cycling and provides more
efficient system operation.
Concord CXi -
Installation