12 5
CENTRAL HEATING SYSTEM
During the first few hours of operation of the central heating
system, check that all radiators are being heated at an even rate.
Should the upper area of a radiator be at a lower temperature than the
base of the radiator, it should be vented by releasing air through the
venting screw at the top of each radiator. Make sure your installer
shows you how to carry out the operation. Repeated venting will
reduce the quantity of water in the system and this must be
replenished for safe and satisfactory operation of the appliance.
Should water leaks be found in the system or excessive venting be
required from any radiator, your installer or heating engineer should
be contacted and the system corrected.
SEALED HEATING SYSTEM
The appliance will be fitted to a sealed heating
system which is pre-pressurised. Your installer will
advise you on the minimum and maximum pressure that
should be indicated on the pressure gauge. See Fig. 3.
Check regularly that this pressure is maintained and
contact your installer or maintenance engineer if there is
a permanent significant drop in pressure indicated on
the gauge. If the system loses pressure it should be re-
pressurised as instructed by the installer (N.B. Maximum
pressure 2.5 bar).
Pressurising The System (See Fig. 2).
(If in doubt leave this procedure to your installer).
Remove the bottom panel to gain access to the
filling loop assembly.
Insert the bayonet end of the filling key into the
corresponding cut outs in the filling loop housing and
twist to lock the key in place.
Turn the grey knob anti-clockwise to allow water
ingress and fill until the required pressure is reached.
Turn the grey knob clockwise to stop filling and
remove. Remove the filling key by lining up the bayonet
end of the key with the cut outs in the filling loop
housing and withdrawing the key.
N.B. The key must always be removed from the
filling loop housing after the system has been filled to
prevent accidental filling and to comply with Bylaw 14
of the Water Bylaws Scheme.
Store the key in a safe place for future use and refit
the bottom panel.
GENERAL NOTES
9
INDICATOR LIGHTS
Mains electricity indicator:
OFF : No mains electricity to the appliance
ON : Mains electricity is connected to the
appliance
Central heating demand indicator:
OFF : No demand for heat to the central
heating circuit
ON : Central heating demand
FLASHING SLOW : Ignition lockout
(once per second)
FLASHING FAST : Appliance fault (other than ignition
(five times per second) lockout)
Domestic hot water demand indicator:
OFF : No demand for domestic hot water
ON : Domestic hot water demand
FLASHING FAST : Air flow fault.
(five times per second)
Central heating and domestic hot water demand indicators:
BOTH FLASHING SLOW : Overheat cut-off
(once per second)
Flame detection indicator:
OFF : Burner off
ON : Burner on
8
OPERATION OF
CONTROLS
A diagnostic system is provided which gives a flashing light
display on the facia panel. Press the reset button to attempt to restart
the appliance. If the appliance does not return to normal operation
then contact your installer/engineer or Worcester Bosch advising of
the appliance serial number and the flashing light sequence, i.e.
which lights flash and at what speed.
More than 30% of all calls made to our contact centre reporting
appliance faults or breakdowns prove to be false alarms, as there is often
a simple explanation for the apparent malfunction.
So, to help you save time and money – not to mention frustration
and inconvenience – please refer to the General Information, Notes and
Lighting Instructions ensuring all controls are set correctly.
If, after following the instructions the appliance still fails to operate
correctly call the Worcester Contact Centre on 08457 256206.
Arrangements will be made for an engineer to call as soon as possible.
If it is known or suspected that a fault exists on the appliance it
must not be used until the fault has been corrected by a competent
person.
CALL-OUT CHARGES
All of our field service engineers are factory trained.
If you request a visit from an engineer and your appliance has been
installed within the last 12 months, no charge will be made for parts
and/or labour, providing:
•The appliance was commissioned correctly on installation.
•An appliance fault is found and the appliance has been installed
within the past 12 months.
A call-out charge will be made where:
•The appliance has been installed for over 12 months, or
•Our Field Service Engineer finds no fault with the appliance (see
note), or
•The cause of breakdown is with other parts of your
plumbing/heating system, or with equipment not supplied by Worcester.
NOTE: Invoices for attendance and/or repair work carried out on
your appliance by any third party will not be accepted.
APPLIANCE FAILS TO
OPERATE
(See also label on inside of appliance front cover).
The appliance is fitted with the following controls:
See fig. 3.
OPERATING SWITCH
In the ‘0’position there is no mains electricity to the
appliance.
In the ‘I’ position mains electricity is connected to the
appliance.
CENTRAL HEATING TEMPERATURE
CONTROL
The position of this knob will determine the temperature of the
water delivered to the radiators between the ‘I’ and ‘MAX’ position.
When the knob is turned anti-clockwise past the ‘I’ position towards
the ‘’(Summer Position), then the appliance will operate in the
HOT WATER mode only and no heat will be delivered to the radiators.
DOMESTIC HOT WATER TEMPERATURE
CONTROL
The position of this knob will determine the temperature of the
water delivered at the domestic hot water taps between the ‘0’ and
the ‘MAX’ position.
By slightly reducing the flow of domestic water from the tap, the
delivery temperature of the water will be further increased. This is of
particular advantage in the winter, for example to increase bath water
temperature. Also this will provide an added advantage of reducing
the delay before hot water is obtained.
FACIA MOUNTED PROGRAMMER (if fitted)
Your installer may have mounted either a mechanical or an
electronic programmer into the facia of your appliance. Operating
instructions are supplied with the programmer.
RESET BUTTON
Press this button in for five seconds if any of the indicator lights
are flashing.
SYSTEM PRESSURE GAUGE
The red needle has been set to show the sealed system pressure
which is required for the appliance to operate effectively. The grey
needle will show the actual pressure in the system.
Fig. 2.
Grey
Knob
Filling Key
Fig. 3. Controls.
Operating
switch
Mains
electricity
indicator
Reset
button
Flame detection
indicator
DHW demand
indicator
Central heating
demand indicator
CH temp
control knob
DHW temp
control knob
System pressure
gauge
26CDi XTRA
