Saunier Duval Combitek F 23 E Installation And Servicing Instructions page 17

SERVICING INSTRUCTIONS
• Close isolating valves on flow and return connec-
tions.
It is not necessary to drain entire heating circuit to
carry out this work.
• Gain access to pump connection as described
in 'To replace main PCB'.
• Pull off pump connector and earth lead.
• Pull out retaining clip from telescopic pump out-
let connection and slide connection upwards to
release from pump.
• Undo and remove two fixing screws and remove
pump retaining bracket from front of pump.
• Grasp pump body, lift upward to disengage from
reversing valve and turn pump to right. Remove
pump by pulling forward and over reversing valve
assembly.
• Discard old pump inlet 'O' ring.
• Apply silicone grease to new 'O' ring supplied,
and fit onto inlet connection on replacement
pump.
• Fit replacement pump in reverse order to re-
moval.
Note: Apply silicone grease to pump outlet con-
nection 'O' ring before assembly.
• Refit pump electrical connection.
• Open isolating valves on flow and return con-
nections, refill, vent and pressurise boiler. Check for
leaks.
To replace pressure gauge
• Drain down heating circuit of boiler only as de-
scribed in 'To replace pump'.
• Undo and remove screw securing pressure
gauge capillary to front section, see diagram 22.
• Carefully pull capillary from front section.
• Undo and remove two screws securing pressure
gauge to lower front panel and remove gauge.
• Fit replacement gauge in reverse order to re-
moval.
• Fit capillary of new gauge to front section using
new 'O' ring supplied.
• Open isolating valves on flow and return connec-
tions, refill, vent and pressurise boiler. Check for leaks.
To replace reversing valve assembly
• Remove pressure gauge capillary as described
previously.
• Remove pump as described previously.
• Remove microswitch assembly as described pre-
viously.
• Remove retaining clip from LHS pipe connection
on front section of valve and disengage pipe.
• Unscrew and disconnect heating flow (centre)
connection at fixing jig.
• Remove retaining clip from heating flow pipe
connection on right of front section.
• Remove flow pipe from boiler.
• Unscrew and disconnect heating return (left
hand) connection at fixing jig.
• Remove retaining clip from expansion vessel pipe
connection at rear of reversing valve assembly and
disengage pipe, pushing pipe back and out of re-
versing valve.
• Undo and remove large screw holding water
valve to back plate of reversing valve assembly,
see diagram 23
Diagram 22
Diagram 23
Diagram 24
• Push water valve back to disengage it from re-
versing valve.
• Unclip and remove loss of water pressure switch
from left of reversing valve assembly, see diagram
24.
• From below boiler, undo and remove three
screws holding reversing valve to bottom plate of
boiler. Remove complete reversing valve assem-
bly from boiler.
• Undo and remove heating return connecting
pipe and hose from rear of reversing valve assem-
bly. Fit hose to replacement reversing valve assem-
bly.
• Fit replacement reversing valve into boiler in re-
verse order to removal.
Note: Use new 'O' rings, retaining clip, filter and
washer provided.
• Unscrew and remove microswitch assembly from
top of replacement reversing valve assembly to
allow refitting of water valve.
17