Worcester 26CDi Xtra, Installation And Servicing Instructions

Page: 3 / 48

An expansion vessel, pressure gauge and pressure relief valve.
A by-pass for the central heating system.
Temperature safety cut-out controls.
A water flow regulator.
A standard horizontal flue assembly giving flue lengths from
100mm to 1000mm.
Optional extension flue kit to provide for flue lengths of up to
2000mm.
An internal system filling loop assembly.
Optional facia mounted electronic or mechanical programmers
or a radio controlled room thermostat.
An optional wall spacing frame to allow pipe runs behind the
appliance.
2.5 ELECTRICAL SUPPLY
Mains supply: 230V~, 50 Hz. , 180 watts.
External fuse: 3A.
Internal fuses: T 2A (F1), and T 1.25A (F2).
2.6 GAS SUPPLY
Check the data plate (located on the inner cover of the appliance)
to ensure the appliance has been set up for the correct gas
supply. The appliance can be set up for either of the following
gases: Natural gas (
G20 ) or propane ( G31 ).
A conversion kit including instructions is available to change
the appliance from one gas to the other.
The boiler requires 2.7m
3
/h (95.3ft
3
/hr) of natural (G20) or
1.03m 3 /hr (40ft 3 /hr) of propane gas (G31) The gas meter and
supply pipes must be capable of supplying this quantity of gas
in addition to the demands of any other appliances being served.
The meter governor should deliver a dynamic pressure of
20mbar (8in wg) for natural gas or 37mbar (14.4 in wg) for
propane.
The complete installation, including the gas meter, must be
tested for soundness and purged. Refer to BS 6891.
2.7 CONDENSATE DRAIN
A condensate drain is provided on the appliance. This drain must
be connected to a drainage point on site. All pipework and
fittings in the condensate drainage system
must be made of
plastic. NO OTHER MATERIALS SHALL BE USED.
The drain outlet on the appliance is 22mm ( 3 /
4
in plastic.)
See fig. 3.
2.8 PACKING
The appliance and flue components are packed in separate
cartons.
2.9 GENERAL INSTALLATION
The appliance is for connection to a sealed primary system only.
The specified ventilation openings made into a wall or
compartment door must not be obstructed.
If the appliance is to be fitted into a compartment then the
compartment must conform to the requirements of
BS 5440:2:1989.
Notwithstanding the instructions given in BS 5440:2:1989, this
appliance may be fitted in a compartment with no vents as long
as the minimum clearances stated in Section 6: Air Supply, are
maintained.
Do not place anything on top of the appliance.
The clearances specified for servicing must be maintained. See
fig. 2.
2.10 FLUE
The appliance has a multi-directional horizontal fanned flue
system.
The Standard Flue assembly length is from 100mm to 1000mm.
The alternative Extended Flue assembly is available, for flue
lengths up to 2000mm Iong.
The flue system inclines 2
1
/
2
° (44mm per metre length)
towards the appliance, to prevent condensate dripping from the
flue terminal.
NB: A white plume of condensate will be emitted from the
flue terminal when the appliance is operating. Refer to
Section 4 “Siting the appliance.”
A terminal guard, Type K2, GC 393 553, is available from Tower
Flue Components, Vale Rise, Tonbridge,TN9 1TB.
Do not allow the flue terminal fitted to the outside wall to
become obstructed or damaged.
A kit for internal fixing of the flue is also available, as an optional
extra.
2.11 CONTROLS
The electronic control system and gas valve modulate the heat
input in response to the central heating and domestic hot water
temperature settings between minimum and maximum.
The ON/OFF switch will turn the mains electricity on and off to
the appliance.
The Central Heating Temperature control knob provides for the
selection of domestic hot water only (turned fully anti-clockwise)
or central heating and domestic hot water (turned clockwise).
The position of the Domestic Hot Water control knob will
determine the temperature of the water delivered to the taps.
A choice of facia mounted programmers is available as an
optional extra. A remote mounted programmer may be
connected to the appliance.
The integral facia displays indicate the status of the appliance.
There is provision for the connection of a mains voltage room
thermostat and/or a frost thermostat.
The electronic controls prevent rapid cycling of the appliance in
the central heating mode.
Frost Protection
The boiler is fitted with an internal frost thermostat which will
protect the boiler from frost damage, as long as the mains switch
on the boiler is in the on position. However, if frost protection is
necessary for the system, please contact Worcester Heat
Systems Technical Helpline. Tel: 0990 266241.
Thermostatic radiator valves can be used in the system.
The appliance incorporates an adjustable by-pass between the
central heating flow and return.
2.12 SYSTEM NOTES
WARNING:
CHECK THAT NO DIRT IS LEFT IN EITHER THE GAS OR
WATER PIPEWORK AS THIS COULD CAUSE DAMAGE TO THE
APPLIANCE. THOROUGHLY FLUSH THE HEATING SYSTEM, AND
THE MAINS WATER SUPPLY IN ACCORDANCE WITH THE
RECOMMENDATIONS OF BS 7593 :1992.
NB: AN INLET WATER FILTER IS FITTED INTO THE MAINS COLD
WATER INLET ON THE APPLIANCE. CHECK THE FILTER IS FITTED
WHEN THE APPLIANCE IS INSTALLED. SEE FIG. 18.
REFER TO SECTION 10 “INSTALLATION,” AND 10.2 “GENERAL
FITTING.” SEE FIG. 16 .
PURGE THE GAS SUPPLY BEFORE FINALLY CONNECTING THE
APPLIANCE.
The water pipe connections throughout a sealed system must be
capable of sustaining a pressure of up to 3 bar.
Radiator valves must conform to the current requirements of
BS 2767: 10.
The relief valve discharge must be directed away from any
electrical components or where it would cause a hazard to the
user.
A drain cock to BS 2879 must be fitted to the lowest point of the
system.
For circuit design purposes it is important that due note is taken
of the information given in Table 3 relating to the available pump
head.
3