29
– Remove sealed chamber cover
– Remove auto air vent
– Refit in reverse order
5.16
3 bar pressure relief valve
– Turn off power supply
– Remove boiler cover
– Isolate flow and return valves
– Drain boiler using drain vent
– Prot ect wiring from any wat er los t
when removing pressure relief valve
– Remove pressure relief valve
– Refit in reverse order using new seals
as required.
5.17
7bar pressure and
temperature relief valve
– Turn off power supply
– Remove boiler cover
– Remove front panel
– Isolate water supply to boiler
– Open hot tap
– Drain storage vessel
– Prot ect wiring from any wat er los t
when removing pressure relief valve
– Disconnect pressure relief pipe
– Important Hold securely the hexagonal
extension before unscrewing the pres-
sure relief valve
– Unscrew pressure relief valve
– Ref it in r ever se r eplacing seals as
required.
5.18 Transducer
– Turn off power supply
– Remove boiler cover
– Isolate flow and return valves
– Drain boiler using drain vent (do not use
pressure relief valve)
– Prot ect wiring from any wat er los t
when removing transducer
– Disconnect plug from transducer
– Unscrew transducer from pipework
– Replace O ring seal
– Replace in reverse order.
5.19 Fan
– Remove burner as described in 5.5
– Remove 4 x 8 mm bolts securing fan to
burner assembly
– Transfer restrictor from old fan to new
fan
– Refit in fan t o burner ensuring the
arrow on the injector is pointing from
the fan to the burner
– Refit in reverse order.
5.20
Storage cylinder
– Turn off power supply
– Remove boiler cover
– Prot ect wiring from any wat er los t
when removing water connections
– Isolate flow and return valves
– Drain boiler using drain vent
– Isolate water supply to boiler
– Drain cylinder
– Remove front panel
– If possible remove RHS panel
– Remove expansion vessel 5.2
– Disconnect cylinder stat
– Disconnect all pipework from cylinder
– Disconnect water supply
– Disconnect DHW connection
– Remove 2 x locknuts from connections
to cylinder
– Carefully lift out cylinder
– Refit in reverse order replacing seals as
requires.
5.21
Cylinder stat (DHW sensor)
– Turn off power supply
– Remove boiler cover
– Isolate water supply to boiler
– Drain cylinder
– Remove boiler cover
– Remove front panel
– If possible remove RHS panel, otherwise
remove expansion vessel as described
in 5.2
– Disconnect DHW sensor
– Unscrew sensor
– Replace in rever se order replacing
seals as required.
5.22 Condensate
trap
– Turn off power supply
– Isolate the gas supply
– Remove boiler cover
– Remove sealed chamber cover
– Remove wire clip securing condensate
pipe to the trap
– Disconnect the pipe
– Disconnect the condensate drain
– Remove nut securing condensate trap
to sealed chamber.
– Refit in reverse order.
5.23 Flow
switch
– Turn off power supply
– Remove boiler cover
– Isolate flow and return valves
– Drain boiler using drain vent (do not use
pressure relief valve)
– Prot ect wiring from any wat er los t
when removing the flow switch assem-
bly
– Remove flow switch cover
– Remove flow switch microswitch
– Remove 2 x clips securing pipe connec-
tions
– Carefully remove pipes
– Refit in reverse order (use silicone
grease to ease refitting of pipes to flow
switch assembly).
5.24 Ignition
transformer
– Isolate boiler from power supply
– Remove 2 screws securing control
panel
– Lower control panel to horizontal posi-
tion
– Remove PCB cover
– Disconnect ignition transformer from
PCB
– Disconnect ignition electrode from igni-
tion transformer
– Remove ignition transformer f ixing
screws
– Refit in reverse order.
