
Supplied By www.heating spares.co Tel. 0161 620 6677
43
221474C
4 Replacement of Parts
Diagram 4.16
ELECTRICAL
CONNECTORS
6370
UNION NUT
FLOW SWITCH
LOCKNUT
VIEW ON ARROW 'A'
FLOW SWITCH
ELECTRICAL
CABLES
THROTTLE
UNION
NUT
ISOLATING
VALVE
WATER
INLET PIPE
ASSEMBLY
WATER
FILTER
FILTER
UNION
NUT
FLOW
SENSOR
'A'
Diagram 4.15
6364
D.H.W.
THERMISTOR
CENTRAL
HEATING
THERMISTOR
4.19 Thermistor - Heating
Gain access, by removing the user control switch bracket, see
diagram 4.3.
Disconnect the cables from the thermistor, see diagram 4.16.
IMPORTANT: Do not remove cable retaining strap.
Unclip the thermistor.
NOTE: When the thermistor is replaced, it must be repositioned at
the same location as before.
The polarity of the electrical connections is not important.
4.20 Thermistor - Domestic Hot Water
Disconnect the cables from the thermistor, see diagram 4.16.
IMPORTANT: Do not remove cable retaining strap.
Unclip the thermistor.
NOTE: When the thermistor is replaced, it must be repositioned at
the same location as before.
The polarity of the electrical connections is not important.
4.21 Safety Valve
Release the water pressure and drain the central heating circuit of
the boiler, refer to Section 1.3 and 1.6.
Remove the pressure gauge, refer to Section 4.13.
Disconnect the union nuts to release the safety valve, see diagram
4.17.
4.22 Water Inlet Filter
Refer to the appropriate parts of Section 4.18.
4.23 Domestic Hot Water Throttle
Release the water pressure and drain the domestic hot water circuit
of the boiler, refer to Section 1.3 and 1.6.
Refer to Section 4.18 to gain access to the throttle.
Remove the cap nut and carefully remove the throttle adjuster, by
unscrewing, it may be necessary to push the throttle adjuster out
from the rear, see diagram 4.18.
Clean if necessary, taking care not to damage the throttle body.
Reset the domestic hot water flow rate refer to Section 11.6 in the
Installation Instructions.
4.24 Mini Expansion Vessel
Release the water pressure and drain the domestic hot water circuit
at the boiler, refer to Sections 1.3 and 1.6
Remove the control housing as diagram 4.1 .
Note. It may be possible, in some circumstance, to remove the mini
expansion vessel by hand.
When refitting use the new sealing washer supplied, see diagram
4.19.
4.25 Automatic Air Vent
Release the water pressure and drain the central heating circuit of
the boiler, refer to Sections 1.2 and 1.6.
Remove the automatic air vent, see diagram 4.20.
SLACKEN THE SMALL CAP ON THE AIR VENT. THIS MUST
NOT BE RETIGHTENED.
When refitting use the new washer supplied.