5
User Guide
USER
EFFICIENT HEATING SYSTEM OPERATION
The boiler is a high efficiency, condensing appliance which will
automatically adjust its output to match the demand for heat.
Therefore gas consumption is reduced as the heat demand is
reduced.
The boiler condenses water from the flue gases when
operating most efficiently. To operate your boiler efficiently
(using less gas) turn the central heating temperature knob
(B) lower. In winter periods it may be necessary to turn the
knob towards a higher temperature position to meet heating
requirements. This will depend on the house and radiators
used.
Reducing the room thermostat setting by 1ºC can reduce gas
consumption by up to 10%.
WEATHER COMPENSATION
When the Weather Compensation option is fitted to the system
then the central heating temperature knob (B) becomes
a method of controlling room temperature. Turn the knob
clockwise to increase room temperature and anti-clockwise
to decrease room temperature. Once the desired setting has
been achieved, leave the knob in this position and the system
will automatically achieve the desired room temperature for all
outside weather conditions.
BOILER FROST PROTECTION
The boiler is fitted with frost protection that operates in all
modes, provided the power supply to the boiler is always
turned on. If the water in the boiler falls below 5ºC, the frost
protection will activate and run the boiler to avoid freezing.
The process does not guarantee that all other parts of the
system will be protected.
If a system frost thermostat has been installed, the boiler must
be set in winter mode, “(there should not be a cross through
the radiator symbol)”, for the system frost protection to run.
If no system frost protection is provided and frost is likely
during a short absence from home it is recommended to leave
the system heating controls or built in programmer (if fitted)
switched on and run at a reduced temperature setting.
For longer periods, the entire system should be drained.
BOILER RESTART
To restart the boiler, when directed in the listed fault codes (see
section 1.9) press the restart button (F). The boiler will repeat
its ignition sequence. If the boiler still fails to start consult a
Gas Safe Registered Engineer.
MAINS POWER OFF
To remove all power to the boiler the mains power switch must
be turned off.
OPERATION MODES
WINTER CONDITIONS - (CENTRAL HEATING AND
DOMESTIC HOT WATER REQUIRED)
Press the mode button until there is not a cross through the
radiator symbol.
The boiler will fire and supply heat to the radiators but will give
priority to domestic hot water on demand.
The domestic hot water preheat will operate if the preheat has
been enabled. If Preheat On is shown at the bottom left of the
display then preheat is enabled, if Preheat Off is shown then it
is disabled.
Summer Conditions -
(Domestic Hot Water only required)
Press the mode button until a cross is shown through the
radiator, but a cross is not shown through the tap.
Set the central heating demand on the external controls to
OFF.
The domestic hot water preheat will operate if the preheat has
been enabled. If Preheat On is shown at the bottom left of the
display then preheat is enabled, if Preheat Off is shown then it
is disabled.
BOILER OFF
Press the mode button until crosses are shown through both
the tap and radiator symbols.
PREHEAT - DOMESTIC HOT WATER
The domestic hot water heat exchanger within the boiler can
be preheated to provide faster delivery of hot water at the tap.
The boiler is factory set with the preheat turned off to give
standard hot water delivery and reduce gas usage.
If required, the preheat can be switched on during installation
for faster domestic hot water delivery. With preheat turned
on, ‘Timed’ is shown on the display as this boiler has a timed
intelligent preheat function which learns the usage patten for
domestic hot water over 24 hours.
It then fires the boiler periodically for a few seconds to maintain
the temperature of the domestic hot water heat in the boiler, as
required to meet the predicted hot water draw-off.
This improves the speed of response for DHW whilst
minimising the use of gas.
CONTROL OF WATER TEMPERATURE
DOMESTIC HOT WATER
The domestic hot water temperature is limited by the boiler
controls to a maximum temperature of 65
º
C, adjustable via the
domestic hot water temperature knob (A).
Approximate temperatures for domestic hot water:
Knob Setting
Hot Water Temperature (approx.)
Minimum
40ºC
Maximum
65ºC
Due to system variations and seasonal temperature
fluctuations domestic hot water flow rates/temperature rise will
vary, requiring adjustment at the tap : the lower the flow rate
the higher the temperature, and vice versa.
CENTRAL HEATING
The boiler controls the central heating radiator temperature
to a maximum of 80
o
C, adjustable via the central heating
temperature knob (B).
Approximate temperatures for central heating:
Knob Setting
Central Heating Radiator
Temperature (approx.)
Minimum
30ºC
Maximum
80ºC
Set to 72°C or less for high efficiency operation.
