Part No. 5106463
41
Domestic Service Cock (Flowsure/F)
1. Close the mains water isolation valve to boiler.
2. Drain the residual water from the hot water
pipework.
3. Undo the nut connecting the domestic service cock
to mains inlet pipework.
4. Undo the nut connecting the domestic service cock
to flow switch pipework.
5. Pull the nuts back, gently ease out the domestic
service cock from the pipework.
6. Fit new domestic service cock in reverse order,
ensuring the direction flow indicator on the domestic
service cock points to flow switch.
7. Open mains water isolation valve, turn on hot water
tap, check connections are sound.
Note: A flow restrictor and filter is fitted in the outlet of
the domestic service cock, ensure the correct colour
flow restrictor is fitted for the correct boiler model,
see Table 1 (page 13).
Flow Restrictor
The flow restrictor cannot be replaced due to its
location inside the domestic service cock, it is
suggested that the domestic service cock be replaced
when required. Follow instructions on replacement in
paragraph covering the domestic service cock above.
Domestic Hot Water Plate Heat Exchanger
(Flowsure/F)
1. Drain the boiler using the boiler drain point provided.
On the F drain approximately one litre of
water from the heatstore tank using the tank drain
point provided, this will prevent excessive residual
spillage from the pipework when disconnecting.
2. Close the mains water isolating valve to the boiler,
drain the residual water from the hot water
pipework.
Flowsure:
1. Remove the flow switch, refer to paragraph, flow
switch replacement in this section.
2. Undo nut on cold inlet pipe feed to PHE, remove
pipe.
3. Undo nut on hot water outlet pipe from the PHE,
remove pipe.
4. Slacken the two screws retaining the DHW flow pipe
to the diverter valve. Undo the nut retaining the
DHW flow pipe to PHE inlet and swing pipe up and
away.
5. Undo the nut retaining the primary return pipe, from
the PHE outlet. Slide the plate heat exchanger back
and out of the boiler.
6. Fit a new plate heat exchanger in reverse order,
ensuring to replace any damaged fibre washers.
F:
1. Undo both nuts retaining the mixer valve and flow
switch assembly to the plate heat exchanger.
Remove assembly, and place aside, ensuring
electrical lead is not strained.
2. Undo both nuts retaining the primary return pipe,
from PHE outlet and shell top return connections.
Remove pipe assembly and place aside.
3. Slacken nut on tank outlet connection, pipe to PHE
inlet. Undo nut retaining pipe and slide to one side.
Remove plate heat exchanger.
4. Fit a new plate heat exchanger in reverse order,
ensuring to replace any damaged fibre washers.
Open all isolation valves, fill the system as described
in Section 2 - Pre-Installation Requirements. Vent air
from the domestic hot water pipework. Open hot water
tap check for correct operation of system.
Note: After the replacement of components, always
check for soundness of connections. Always carry
out a full functional check of the system.
Servicing & Maintenance
