Disconnect the DHW sensor as described in (19.4).
Remove the screw securing the left part of the
hydroblock to the combination boiler (Figure 57).
Fit the replacement hydroblock parts in reverse
order to removal ensuring all seals are correctly
located and replaced if necessary.
Open the isolating valves on the flow and return
connections, refill, vent and pressurise boiler
ensuring all joints are sound.
19.20 Filter.
Switch off the electrical supply to the boiler.
Close the domestic cold water supply valve below
the boiler (Second valve on the right)
Open a hot water faucet and drain the domestic
hot water system.
Disconnect the valve connection from the boiler
Either pop out the filter with a screw driver or
disconnect the filter housing from the bottom of
the hydroblock using a 24mm spanner.
Pop out the filter and clean or replace as
necessary.
Reassemble the components in reverse order.
Open the valve and check for leaks.
19.21 Flow sensor
Remove the flow sensor using a pair of pliers.
Fit a replacement sensor in reverse order to
removal.
Figure 58
Figure 59
Figure 57
UNCLIP
TO REMOVE
ELECTRICAL
CONNECTION
FLOW
SENSOR
Page 31
19.22 Three way valve motor
Ensure that the electric supply to the boiler is
switched OFF.
Remove the electrical connection to the motor.
Remove the clips connecting the valve to
hydroblock.
Fit the replacement valve in reverse order
ensuring the valve is fitted properly.
Figure 60
THREE WAY
VALVE MOTOR
ELECTRICAL
CONNECTION
CLIP
31