Technical data

58
Linea 24 & 28
11.6.6 Reduce the domestic water flow rate to ap-
proximately 3-4 litres/min. Turn the domestic
control knob slowly to minimum the boiler
output will reduce to the minimum setting. If
low flame cannot be established in this way,
turn off the electricity supply, and disconnect
a grey wire from the modulator coil. Switch on
the electricity supply, the boiler will now light at
the minimum setting.
11.6.7 When low flame is established the pressure
reading should be :
24
5.1mbar
(Plus or minus 0.5mbar)
28
4.3mbar
(Plus or minus 0.43mbar)
If it is different adjustment should be made in
accordance with the instructions in 8.23.
11.6.8 If a grey wire was disconnected from the
modulator coil to check the minimum setting,
turn off the electricity supply and reconnect
the wire.
11.7 Maximum Rate in Central Heating Mode
The Linea range does not require any adjust-
ment to the maximum heat requirement of the
system load.
11.8 Setting the Minimum Rate for Central Heat-
ing
Turn off the main electrical supply.
Gain access to the electrical terminal blocks
(5.7.2) Fig. 19.
Identify jumper plug position JP9 on circuit
board fig. 38 and fit a temporary jumper tag.
Turn the mode selector switch to the
position, ensure that the room thermostat
and/or timeclock (if fitted) are calling for heat.
Turn the heating thermostat to maximum and
ensure the appliance ignites.
Identify minimum adjustment button on pcb
(fig. 38).
Press the minimum adjustment button once.
The boiler will operate in central heating mode
at a minimum gas pressure. An LED on the
PCB will flash red to confirm the appliance is
in central heating minimum mode.
The gas pressure should now be:
24
6.5 mbar
plus or minus 0.65 mbar
28
5.5 mbar
plus or minus 0.55 mbar
If the reading is incorrect it should be adjusted
as follows:
Identify the minimum adjustment
potentiometer on the PCB (fig. 38).
With the boiler still in central heating mode
and the burner at the minimum rate, using a
small screwdriver turn the potentiometer
clockwise to increase & anti-clockwise to de-
crease the gas pressure.
When all is adjusted, press the minimum
adjustment button once (the appliance will
return to normal operation). Turn the appli-
ance off and remove the temporary jumper
connected to plug JP9.
11.9 Soft light ignition and range rating for central
heating is fully automatic, no adjustment is
necessary.
11.10 Turn mode selector to the OFF position, dis-
connect pressure gauge, re-tighten screw.
Relight boiler.
11.11 Re- check for gas soundness.
11.12 Replace electrical controls panel.
11.13 Refix the boiler casing (fig. 25).
11.14 Hinge up controls facia and secure using the
2 screws (fig. 26).