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9.14
DHW FLOW SWITCH BODY
9.13
DHW HEAT EXCHANGER
38
WATER HOUSING GROUP SET
a)
Remove the casing panels and lower the control box as
described in section 9.1 step (a).
a)
Remove the casing panels and lower the control box as
described in section 9.1 step (a).
b)
Remove the complete control box and baseplate as described
in section 9.13 steps (b) and (c).
c)
Isolate the cold water inlet valve and drain the DHW circuit by
opening all DHW taps.
d)
Refer to Figure 38. Unscrew the two screws securing the switch
body to the main brass block. note the position of the
alignment pin.
e)
Remove the two spring clips which secure the pressure sensing
pipes into the switch body and pull out the pipes, taking care
to collect any residual water.
9.11
THEMISTORS - DHW OR HEATING
The thermistors are immersed in the waterways hence slight water
loss is likely during this operation. Provision should be made to
collect a small amount of water underneath the appliance.
a)
Remove the casing panels and lower the control box as
described in section 9.1 step (a).
b)
Isolate the appliance from the system as follows:
If replacing DHW thermistor turn off the inlet water valve (see
section 5) and open all DHW taps to empty the DHW circuit).
If replacing CH thermistor, turn of the boiler flow and return
from the system using the isolation valves as shown in section 5.
c)
Unclip and remove the electrical connector plug from the
thermistor. Unscrew the thermistor from the waterway.
d)
Replace the thermistor and re-assemble in reverse order.
Re-commission the system as described in section 5.
b)
Unclip the pressure gauge and the PCB connector plugs from
the control box, disconnect the mains electrical connection
(and external controls, if fitted) unclip the controls housing
from the baseplate, and remove it from the boiler.
c)
Unscrew and remove the baseplate (4 screws).
d)
Turn the CH flow and return valves to the closed position to
isolate the boiler (see section 5.1), then drain the appliance
using the drain cock provided on the CH flow valve.
e)
Isolate the cold water inlet valve and drain the DHW circuit by
opening all DHW taps.
f)
From underneath the appliance, remove the two spring clips
securing the bypass pipe, and pull out the pipe. (Collect any
discharged water).
g)
Unscrew the two socket head cap screws supporting the heat
exchanger (from above the heat exchanger - see Figure 38)
and push the heat exchanger downwards to release it.
(Collect any discharged water).
h)
Replace the heat exchanger, then re-assemble in reverse order
and re-commission the heating and hot water systems as
explained in section 5.
i)
Check for leaks.
PLATE HEAT
EXCHANGER
SOCKET HEAD
CAPSCREWS (2)
(Secure plate
heat exchanger)
DHW
FLOWSWITCH
(Pink Wires)
LARGE BRASS NUT
(Water flow
regulator behind)
DHW PRESSURE
SENSING PIPES
PRESSURE RELIEF
VALVE
BYPASS
(Underneath)
FLOW SWITCH
SECURING
SCREWS (2)
PRIMARY/FLOWSWITCH
(Violet Wires)
LARGE
HEXAGON
NUT
‘O’ RING SEAL
FILTER
WATER FLOW REGULATOR
(Small diameter towards
small hexagonal nut)
SMALL
HEXAGONAL
NUT
PUMP
DHW
THERMISTOR
(Black Wires)
CH
THERMISTOR
(Grey Wires)
9.12
WATER FLOW REGULATOR
a)
Remove the casing panels and lower the control box as
described in section 9.1 step (a).
b)
Isolate the cold water inlet valve (see section 5) and drain the
DHW circuit by opening all DHW taps.
c)
Make provision to collect any discharged water and unscrew
and remove the large brass nut (Fig. 38) supporting the
regulator assembly.
d)
Unscrew the small nut at the opposite end of the assembly
and carefully remove the plastic water regulator. Replace the
water flow regulator. Ensure that the regulator is the correct
way around (Fig. 38). The filter should be cleaned.
e)
Carefully re-assemble in reverse order then re-commission the
DHW circuit as described in section 5.
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