Technical data

13.1 Tell the user how to operate the appliance and hand over the
Users Instructions leaflet and the completed Benchmark log book.
13.2 Tell the user what to do if the heating system is not to be
used in frosty weather. Also tell the user that if the appliance is
not to be used for long periods during frosty weather, the system
must be drained and the gas and electricity supplies turned off.
13.3 Tell the user the Sealed System set pressure if applicable.
13.4 Tell the user of the importance of regular servicing.
Worcester offer a comprehensive maintenance contract.
13.5 Set the system controls to the users requirements.
13.6 If an external programmer has been fitted instruct the user
how to set the programmes.
13.7 Tell the user about the safety devices and any hazard notices.
To ensure continued efficient operation of the appliance it must
be checked and serviced as necessary at regular intervals. The
frequency of servicing will depend upon the particular
installation conditions and usage, but once per year should
generally be adequate. The extent of the service required by
the appliance is determined by the operating condition of the
appliance when tested by fully qualified engineers.
It is the law that any service work must be carried out by
competent engineers such as British Gas or Corgi registered
personnel.
14.1 PRE-SERVICE INSPECTION.
14.1.1 Check that the flue terminal and the terminal guard, if
fitted, are clear.
If the appliance is in a compartment check that the ventilation
openings in the compartment door or walls are clear. Refer to
Section 6, Air Supply.
Check the operation of the pressure relief valve. Reset the system
pressure if necessary.
Check the expansion vessel pressure and reset as necessary.
Check the system and remake any joints or fittings which show
signs of leakage. Refill, vent and re-pressurise sealed systems as
described in Section 12, Commissioning.
Operate the appliance and the system taking note of any faults.
14.1.2 MEASUREMENT OF FLUE GASES.
For consistency of flue gas measurements it is necessary to have a
constant maximum output and the appliance to be at equilibrium.
Switch the temperature controls to MAX.
Hinge down the facia into the service position. Refer to Fig. 14.
Wait until the appliance reaches equilibrium (approx. 10
minutes).
Remove the cap from the sensing point at the top left of the
inner casing and connect the gauge. See Fig. 16.
Expected measurements should be between:
CO: 0.001 and 0.003%.
CO
2
: 6.7 and 7.0%.
After taking the measurement:
Disconnect the gauge
Replace the sealing cap.
Put the facia back in to its normal position.
Reset the controls.
SAFETY:
Disconnect the electrical supply at the mains and turn off the
gas supply at the gas service cock on the appliance before
servicing the appliance. See Fig.16.
After completing the service always test for gas soundness as
indicated in BS 6891.
14.2 DISMANTLE THE APPLIANCE.
To carry out a full and comprehensive service of the appliance
remove the following parts to gain access to the components
which need to be checked or serviced.
(a) Cabinet Front Panel.
Lift the panel to clear the top locator and the kick strip. See Fig. 14.
(b) Facia and Control Box.
Remove the cabinet front panel. Unscrew the two screws
securing the facia to the outer edges of the cabinet, accessible
under the facia. Ease the facia forwards on the slide rails until
fully extended. Lift the facia and control box upwards through
90° into the Service Position. Lodge in the Service Position on the
outer locations. See Fig. 14.
(c) Expansion Vessel.
Remove the cabinet front panel.
Unscrew one screw securing the expansion vessel support
bracket to the right hand side panel and carefully lower the
vessel. See Fig. 16.
(d) Inner Casing Cover.
Repeat operations a, b and c. Unscrew the four screws securing
the cover to the inner casing and lift off. See Fig. 16.
(e) Fan.
Repeat operations a,b,c and d. Ease the two electrical
connections from the fan motor and the two flexible pipes from
the venturi housing. Unscrew the two screws securing the front
of the fan mounting plate to the flue hood. Ease the fan
assembly out of the flue bend or flue adaptor by gently pulling
the mounting plate forwards about 20 mm to clear the flue bend
or flue adaptor. Remove the fan and mounting plate assembly
from the inner casing. See Fig. 36.
(f) Flue Hood.
Repeat operations a,b,c,d and e. Unscrew the two screws
locating the front of the flue hood to the combustion chamber
cover. Ease the flue hood forwards about 15 mm to clear the rear
locator. Remove the flue hood off the heat exchanger and clear of
the inner casing. See Fig. 36.
(g) Combustion Chamber Cover.
Repeat operations a,b,c,d,e, and f. Unscrew the four screws
securing the combustion chamber cover and remove the cover.
See Fig. 36.
(h) Burner.
Repeat operations a,b,c,d,e,f and g. Unscrew the two screws
securing the pilot bracket. Unscrew the two screws securing the
front of the burner and the spark electrode earth lead to the
burner bracket located inside the inner casing. Remove the
burner by easing forwards and upwards off the main burner
injector and clear of the pilot bracket. See Fig. 36.
(i) Pilot.
Repeat operations a,b,c,d,e,f and g. Unscrew the two screws
securing the pilot bracket to the burner bracket. Unscrew and
remove the flame sense electrode. Unclip the spark igniter and
remove.
Support the pilot bracket with a suitable tool. Unscrew the pilot
pipe union nut and ease the pipe clear of the bracket. Remove
the pilot injector from the pilot bracket. See Figs. 34 and 36.
14. Inspection and Servicing
13. Instructions to the User
32
Fig. 35. Facia Controls.
1
2
3
4
5
6
1. Power light. 5. Heating temperature contol
2. Heating demand light. and reset control.
3. Hot water demand light. 6. Twin channel programmer
4. Hot water temperature control. (optional).