Glow-worm SwiftFlow 120 Servicing Instructions page 22

4.15 Multifunctional Control and Gas/Air
Ratio Unit Assembly: diagram 4.12
Remove control housing, see diagram 4.1.
Remove the piezo bracket, see diagram 4.3.
Disconnect the two electrical connectors at the front of
the multifunctional control.
Disconnect the boiler overheat cutoff connectors.
Disconnect the thermocouple nut at the
multifunctional control.
Disconnect the pilot supply tube at the
multifunctional control.
Disconnect the gas/air ratio unit tubes at the
bulkhead connectors.
Remove the four, right hand, extended hexagon screws
from the multifunctional control.
Break the gas connection at the wall frame.
Remove the multifunctional control valve and gas/air
ratio unit assembly, taking care not to damage the tubes.
Multifunctional Control
Remove the four, left hand, extended hexagon screws
from the multifunctional control.
Discard the "O" rings and fit the new ones, supplied.
Check and adjust the main burner gas pressure in both
the domestic hot water and central heating modes, refer
to "Commissioning" in the Installation Instructions.
Gas/Air Ratio Unit Assembly
Disconnect the gas/air ratio unit sensing tubes.
Remove the two securing screws, see diagram 4.12.
4.16 Central Heating Selector Switch
Slacken the piezo bracket securing screws and remove
the bracket from the keyhole slots, see diagram 4.3.
Pull the leads from the switch.
To remove the switch press in the tabs on each side.
The polarity of the electrical connections is not
important.
221045A
Supplied By www.heating spares.co Tel. 0161 620 6677
4 R e p l a c e m e n t o f P a r t s
HEXAGON
SCREWS (4)
SCREW (2)
GAS/AIR
RATIO UNIT
SENSING
TUBE NUTS
22
GAS/AIR
RATIO UNIT
TUBE NUTS
ELECTRICAL
CONNECTORS
BOILER
OVERHEAT
CUTOFF
CONNECTOR
MULTIFUNCTIONAL
CONTROL
'O' RING
GAS/AIR
RATIO UNIT
BOILER
OVERHEAT
CUTOFF
CONNECTOR
HEXAGON
SCREWS
(4)
PILOT
SUPPLY
TUBE
THERMO-
COUPLE
NUT
GAS
CONNECTION
'O' RING
VENTURI AIR
SIGNAL TEST
POINT
Diagram 4.12