Potterton Performa 28i, Installation And Servicing Instructions, Page: 34 / 48

12.0 Changing Components
34
12.15 Pressure Gauge (Figs. 57 & 58)
1. Drain the primary circuit and undo the nut on
the pressure gauge capillary.
2. Remove the timer cover and ease the timer
wiring aside. Undo the screws securing the
gauge retaining bracket.
3. Remove the bracket and gauge assembly.
Depress the barbs on the side of the gauge and
remove the retaining bracket.
4. Reassemble in reverse order.
12.16 Expansion Vessel &
Pre-Heat Store
(Fig. 59)
1. To replace the expansion vessel and pre-heat
store it is necessary to remove the boiler from
the wall.
2. Drain the system and undo all gas and water
connections. Remove the flue elbow.
3. Lift the boiler off the wall plate and lay it on
either side on a clean flat surface.
4. Undo the unions on pipe ‘A’ and remove the
pipe (Fig. 59).
5. Undo the union on pipe ‘B’ connected to the
vessel (Fig. 59) and remove the locknut securing
the vessel spigot to the boiler chassis.
6. Undo the screws and remove the appliance
upper cross member. Slide the expansion vessel
and insulation out of the retaining clips.
7. Reassemble in reverse order using new
sealing washers. Fully recommission the
appliance and system.
12.17 Spark Generator (Fig. 60)
1. Pull the electrode lead off the spark
generator. Remove the screws and spring
washers securing the generator to it’s mounting
bracket.
2. Pull the rubber shroud off the generator input
plug and disconnect the plug.
3. Reassemble in reverse order.
Pressure Gauge
Timer Cover
Pressure Gauge
Capillary
Gauge Retaining
Bracket
Expansion Vessel &
Pre-Heat Store
Retaining Clip
Appliance Upper
Cross Member
Vessel Spigots
Boiler
Chassis
Lock Nut
Electrode Lead
Spark Generator
Mounting Bracket
Fig. 57
Fig. 58
Fig. 59
Fig. 60
Pipe ‘B’
Pipe ‘A’