Technical data

18. Gas Valve. See Figs. 8, 16 and 45.
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel and lower the expansion vessel
as described in Section 14.2 a, b and c.
Turn off the gas supply at the service cock.
Disconnect the pilot pipe at the gas valve and carefully move
to one side.
Unscrew the union securing the outlet flange connection to
the side of the of the gas valve. Unscrew the four slotted hex
head screws at the gas service cock at the valve. Support the
valve and unscrew the retaining screw from the igniter unit
and remove. Carefully pull off the leads from the valve.
Fit the replacement gas valve in the reverse order ensure the
'O' rings are renewed. Reconnect the electrical connections
and the igniter unit. Reassemble the appliance in reverse
order.
Turn on the gas supply at the service cock and check for gas
soundness.
Re-commission the appliance and set the burner setting
pressures. Refer to Section 12: Commissioning and Fig. 31.
19. Pilot Filter.
If problems are experienced with the pilot filter fit a replacement
gas valve as described in Section 15.3.-18.
20. Circulating Pump. See Figs. 16 and 46.
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel, place the facia and control box in the
Service Position and lower the expansion vessel as described in
Section 14.2 a, b and c.
Drain the heating circuit as described in Section 15.2 a.
Remove the pump cover and disconnect the electrical connections.
Release the cable clamp and remove the cable.
Withdraw the two securing clips from the pump body. Ease the
pump forwards about 10 mm off the “O” ring seals and remove from
the appliance.
CAUTION: There will be a small quantity of water remaining in the
pump and pipework. Follow the procedure as described in 15.2.
Discard the pump and “O” ring seals.
Fit new “O” ring seals. Fit a replacement pump in the reverse order
taking care to ensure the securing clips are properly entered into the
slots and not scoring the O-rings on entry. A smear of lubricant on
each O-ring will ease the re-assembly. Check the pump head is set to
maximum.
The pump head is a Grundfos 15/60. A replacement head may be
transferred to the special body. Take care not to mark the mating surfaces.
Reconnect the cable and refit the cable clamp.
Open the valves, fill and repressurise the system as described in
Section 12.2.
Reassemble the appliance in the reverse order.
21. Water Diverter Valve and Coil. See Figs. 16, 46 and 47.
Check that the electricity supply to the appliance is turned off.
Remove the cabinet front panel and lower the expansion vessel
as described in Section 14.2 a. Remove the facia as described in
Section 15.1 .
Diverter Valve Coil.
Carefully remove the clip securing the locking bar and withdraw
the coil.
Unplug the connector from the coil.
Fit the new coil ensuring that the clip is correctly fixed.
Diverter Valve
Note: It is not necessary to disconnect the electrical cable. The
cable length is sufficient to allow the pump head to rest on top of
the appliance. Do not allow the pump head to be suspended by
the cable. Secure the pump head.
Unplug the connector at the diverter valve.
Using a pair of long nose pliers, remove the two clips securing
the 6 mm copper pressure pipe, to the top left hand corner of the
valve and pump connection. Retain the clips. Ease the pressure
pipe out of the connections and clear of the appliance.
Retain the pressure pipe.
Unscrew the four fixing screws securing the water diverter valve
to the bottom manifold. The bottom right hand screw is
accessible using a “chubby” type screwdriver. Remove the water
diverter valve clear of the appliance. Discard the valve and “O”
ring seals. Retain the fixing screws.
CAUTION. There will be a small quantity of water remaining in
the valve and lower manifold. Follow the procedure as described
in Section 15.2.
NOTE: Three new “O” ring seals are provided with the
38
Gas service
cock
Gas inlet
union fitting
Unscrew retaining screws from the
solenoid electrical connection plugs. Pull
each plug off its respective set of terminals
Replace the O-ring
seal when changing
the gas valve
Fig. 45. Gas valve.
Cable
clamp
Remove
pump cover
and
disconnect
electrical
connections
Pump head. To
remove ease
forwards about
10mm off the “O”
ring seals
Flat clip
securing pump
inlet pipe
Securing
clip
Open vent
connection
(if fitted)
Warning: There will be a small quantity of
water remaining in the pump and pipework
Open vent
pipe (if fitted)
Two “O” ring
seals. Remove
and replace
with new “O”
ring seals
Securing
clip –
copper
pressure
pipe
Securing
clip
Copper
pressure
pipe
3
Fig. 46. Circulating pump.
4