Operating instructions
1.0 Operating the Boiler
6
2
1
0
4
3
bar
2
1
0
4
3
bar
2
1
0
4
3
bar
2
1
0
4
3
bar
ON/OFF
Selector Switch
OFF Position
Fig. 16
Normal Pressure (when cold)
Normal Pressure (operating)
Fig. 12
Fault
Fig. 13
Below Minimum
Fig. 14
Fig. 15
Pressure Gauge
1.7 Central Heating System Pressure
1. The water pressure in the central heating system is
indicated by the pressure gauge.
2. With the system cold and the boiler not operating the
pressure should be at least 0.5 bar. During operation the
pressure should not exceed 2.5 bar, and will normally be
between 1.0 and 2.0 (Figs. 12 & 13).
3. A pressure of 3 or greater indicates a fault. The safety
pressure relief valve will operate, at a pressure of 3 (Fig.
14). It is important that your Installer or Service Engineer
is contacted as soon as possible.
4. The MINIMUM pressure for correct operation is 0.5. If
the pressure falls below 0.5, this may indicate a leak on the
central heating system (Fig. 15). Error Code E119 will be
shown on the display.
1.8 To Shut Off the Boiler
1. For short periods: Turn the selector switch to the OFF
position (Fig. 16).
2. For long periods: Turn off the selector switch (Fig.16),
electricity and gas supplies.
If your home is to be left unoccupied for long periods
during cold weather the boiler and whole system should
be drained unless there is additional frost protection.
3. Your installer will advise you about frost protection and
draining the system.
IMPORTANT: When the selector switch is in the ‘0’
(Off) position the electrical supply to the boiler is
isolated. The boiler will not operate and the integral
timer will require resetting once the selector switch is
set to either Position (i) or Position (ii).
1.9 Boiler Frost Protection Mode
1. The frost protection feature will operate when the
selector switch is in the central heating and domestic hot
water mode.
The gas and electrical supplies to the boiler must be on and
the system pressure must be within the range described
above.
2. If the system temperature falls below 5°C, then the
boiler will operate until the water temperature has been
raised.