53
9.21
TIME CLOCK
Refer to Figur
es 53
a)
Ensur
e supply voltage is isolated.
b)
Remove the decorative fr
ont panel, unscrew and lower the
control fascia panel.
c)
Unplug the electrical leads fr
om the PCB. Refer to section 7.
d)
Unplug the four electrical leads fr
om the back of the clock.
e)
Remove the four r
etaining screws and withdraw the clock from
the control panel.
f)
Fit the new clock and r
e-assemble in reverse order.
Refer to Figur
e 28
a)
Ensur
e supply voltage is isolated.
REGULATOR AND DHW FILTER
9.22
DHW FLOW SWITCH, DHW FLOW
54
9.23
DRAINING THE APPLIANCE
Refer to Figur
es 18, 44 & 54
a)
Befor
e draining, give the appliance a brief CH demand, to
ensure the diverter valve is in the CH position.
b)
Ensur
e supply voltage is isolated.
c)
If not draining the entir
e CH system, close the CH flow and CH
return water isolating cocks.
d)
Close the DHW r
eturn water-isolating cock.
e)
Drain down the CH system fr
om the external drain point, and
drain the boiler using the manual drain tap on the CH flow water
isolating cock (figure 18), in conjunction with the manual bleed
valve located on the top LHS of the heat exchanger; refer to Figures
44 and 54.
f)
Wher
e the DHW circuit is to be worked on, close the DHW inlet
isolating cock, open a DHW tap at the lowest point in the system
and allow the pressure to dissipate. Close this tap again.
b)
Remove the electrical lead to the DHW flow switch.
c)
Close the DHW inlet isolating cock, open a DHW tap at the
lowest point in the system and allow the pressure to dissipate. Close
this tap again.
d)
Undo the nut connecting the DHW flow switch to the DHW inlet
isolating cock.
e)
Undo the nut connecting the DHW flow switch to the water feed
pipe, and remove the DHW flow switch, (containing the DHW Flow
Regulator), and DHW Filter.
f)
The assembly can now be flushed clean using water
, and parts
replaced as necessary.
g)
Re-assemble in r
everse order, using a new fibre washer; ensure
that all joints and seals are correctly re-fitted.
h)
Open the DHW inlet isolating cock and vent air fr
om the system
by opening each hot water tap in the house in turn.
39
