Technical data

18
Note: fit expansion vessel pipe and loss of water
switch to reversing valve assembly before pump,
to ensure that it is correctly located. Apply silicone
grease to all 'O' rings and hoses prior to assembly.
• Open isolating valves on flow and return con-
nections, refill, vent and pressurise boiler. Check for
leaks.
To replace reversing valve front section
• Remove pressure gauge capillary as described
previously.
• Remove pipe connections from either side of
reversing valve front section, refer to previous sec-
tion.
• Move short selector lever on front of valve to left
hand position.
• From below boiler, undo and remove single screw
holding reversing valve front plate to bottom plate
of boiler.
• Undo and remove six screws holding front sec-
tion to rear section of reversing valve, see diagram 25.
• Remove front plate complete with pump bracket
and then front section from reversing valve, along
with rubber sealing gasket.
• Assemble bypass valve provided and fit into hole
in underside of replacement front section. Fit 'U'
shaped retaining clip.
Note: Use bypass valve fitted to original front sec-
tion for guidance.
• Fit replacement front section, with gasket, to rear
section.
• Locate front plate and replace six fixing screws.
Take care to evenly tighten screws ensuring they
are not cross threaded.
• Refit pipe connections to either side of front sec-
tion using new 'O' rings provided. Apply silicone
grease to 'O' rings before fitting.
• Refit pressure gauge capillary in reverse order to
removal.
• Ensure short selector lever on front of valve is set
to right hand position.
• Open isolating valves on flow and return con-
nections, refill, vent and pressurise boiler. Check for
leaks.
To replace loss of water switch
• Drain down heating circuit of boiler only as de-
scribed in 'To replace pump'.
Note: It is not necessary to drain entire heating cir-
cuit to carry out this work.
• Pinch plastic cover to release retaing clips and
remove cover from switch. Pull plug lead from
switch terminals.
• Remove clip holding switch into left side of re-
versing valve assembly.
• Pull switch out of reversing valve assembly, see
diagram 24.
• Fit replacement switch in reverse order to re-
moval, using new 'O' ring provided and aplying sili-
cone grease to 'O' ring before fitting.
• Reconnect plug to switch terminals.
• Open isolating valves on flow and return con-
nections, refill, vent and pressurise boiler. Check for
leaks.
Diagram 25
Cla 007
To replace water valve or diaphragm
• Drain down hot water circuit of boiler only as
described in 'Routine Cleaning and Inspection'.
• Remove microswitch assembly as described pre-
viously.
• Remove clip holding connecting pipe in rear of
water valve. From below boiler, grip clip with long
nosed pliers and pull down.
• Using long nosed pliers, slide pipe away from
water valve into brass cold water inlet connection.
• Remove clip holding pipe to heat exchanger in
rear of water valve. From front of boiler, gripclip with
long nosed pliers and pull upwards.
• Unscrew and remove large screw holding water
valve to back plate of reversing valve assembly,
see diagram 23.
• Disengage water valve from reversing valve and
remove from boiler.
Note: When disengaging water valve from heat
exchanger pipe, check that non-return valve is not
held on end of pipe. If so, carefully separate pipe
from valve to ensure that small spring and plunger
do not fly out and are lost.
• To replace diaphragm, undo five screws and
separate main components of water valve.
• If white diaphragm cover is to be replaced, sepa-
rate original from water valve end casting and fit
replacement cover.
• Fit replacement diaphragm , making sure that
metal disc FACES diaphragm cover and beaded
edge of diaphragm is correctly fitted in correspond-
ing groove in both cover and plastic housing, see
diagram 26.
• Reassemble water valve, evenly tightening five
screws.
• Fit water valve actuating pin into hole in dia-
phragm cover, through nose end of valve and and
push in until flush, or slightly below, nose end of
valve.
Note: Apply silicone grease to pin before fitting.
• Refit water valve to boiler, locating nose end into
rear of reversing valve assembly, 'springing' heat
exchanger pipe to gain clearance as necessary.
Fit large water valve retaining screw but do not
tighten fully at this stage.
• Apply silicone grease to 'O' ring and fit onto end
of heat exchanger pipe. Fit pipe into water valve
by pulling it forward. Make sure that 'O' ring is cor-
rectly located.
• Whilst holding pipe in rear of water valve, fit re-
taining clip. This should easily clip over pipe and
SERVICING INSTRUCTIONS