Adjust the central heating by-pass valve until the same
temperature difference is obtained. See Fig. 24. This should be
carried out with only a single radiator operating. If thermostatic
radiator valves are fitted then one radiator should be left
uncontrolled. The bypass valve should never be fully closed.
Set the room thermostat to minimum and check that the burner
goes out. Reset the room thermostat to maximum and the burner
will re-light and follow the normal operating procedure.
Check for proper ignition of the burner after a break in the gas
supply. Turn off the gas service cock and wait for 60 seconds. The
burner will go out but sparking from the electrode will continue
for 10 seconds when the appliance will enter a ‘lockout’ state.
Carefully open the gas service cock, press the lockout reset button
and observe the burner re-light and follow the normal sequence of
operation. Refer to Fig.25.
Set the Operating Switch to OFF.
Turn off the gas service cock and the electrical supply to the
appliance.
Drain the system while the appliance is still hot.
Refill, vent and, with a sealed system, re-pressurise as described in
Section 13.2.
Domestic Hot Water and Central Heating
Turn on the electricity supply to the appliance and open the gas
supply cock at the appliance.
Set the Operating Switch to ON. If a programmer is fitted, set the
domestic hot water to Continuous or 24Hrs and the central heating
to ON. The burner will light and heat will pass into the system. Set
the DHW temperature to MAX and turn on a hot water tap and
check that fully heated hot water is discharged from the tap.
Close the tap and the burner will go off. The appliance will then
return to the central heating mode and automatically balance
with the system requirements.
Set the Operating Switch to OFF and the burner will go out.
13.5 COMPLETION OF COMMISSIONING
Disconnect the pressure gauge from the gas valve and tighten the
test point screw.
Restart the appliance and check for gas soundness around the
test point screw.
Refit the cabinet front panel.
If the appliance is being passed over to the user immediately, refer
to Section 14 - Instructions to the User.
If the appliance is to be left inoperative, check that the Operating
Switch is set to OFF. Turn off the gas service cock.
For short inoperative periods, leave the appliance under the
control of the built in frost thermostat or the remote frost
thermostat (if fitted) or leave operating continuously with the
room thermostat set at 6°C
Do not switch off the electricity supply.
If there is any possibility of the appliance and the system being
left totally unused in freezing conditions then switch off the gas
and electricity and drain the appliance and the system.
14.1
Tell the user how to operate the appliance and hand over
the Users Instructions leaflet.
14.2
Tell the user what to do if the heating system is not to be
used in frosty or freezing weather.
14.3
Tell the user the sealed system set pressure.
14.4
Tell the user of the importance of regular servicing.
Worcester Heat Systems Ltd. offer a comprehensive maintenance
contract.
14.5
Set the system controls to the user’s requirements.
14.6
If an external programmer has been fitted which has a
programmable domestic hot water facility then it is suggested
that this be set to Continuous or the equivalent
14.7
Tell the user about the safety devices and hazard notices.
14. Instructions To The User
17
Fig. 25. User controls.
C.H. demand
indicator
D.H.W. demand
indicator
Mains
indicator
Mains
switch
C.H. temp
control
knob
D.H.W.
temp control
knob
System
pressure
gauge
Reset
button
Flame
indicator
Summary of Contents for 24CDi BF
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