Potterton Performa 28i Installation And Servicing Instructions page 25

Pressure Test Point
Sealing Screw
Fig. 34
Adjuster Tube
Locknut
Adjuster Tube
Minimum Rate
Adjuster Screw
Modulator
Spring Clip
Fig. 35
Selector Switch
30° 40° 50° 60° 70° 80°
Reset
Power On
Neon
Central Heating
Temperature Control
Fig. 37
Gas Valve
2
bar
Fig. 36
Off
2
On
Preheat
bar
Hot Water
Temperature Control
9.0
9.2
1. Turn on the gas and electrical supplies to the
boiler and ensure that all external controls are
calling for heat.
2. Set the temperature control to maximum and
the selector switch to the OFF position (Fig. 37).
3. Slacken the pressure test point sealing screw
(Fig. 34) on the gas valve and connect a pressure
gauge.
4. Undo the screws securing the inner door panel.
Lift the panel slightly to disengage it from the
studs on top of the case and remove the panel.
5. Turn the selector switch fully anticlockwise
against the spring pressure to the reset position
and hold for 2 seconds to reset the boiler.
6. Turn the selector switch to theCentralHeating
and Domestic Hot Water position (
power ON neon (
7. Turn on a hot water tap to give a flow rate of at
least 10 l/min.
8. the pressure should be as quoted in Section
4.0 Technical Data. If not, check that the gas
supply pressure is correct (Natural Gas 20mbar,
Pressure
Butane 30mbar and Propane 37mbar).
Gauge
9. The pressure can be adjusted if required.
10. To check minimum pressure first remove one
of the modulator wires.
Adjusting the Pressure (Fig. 35)
11 Prise apart the spring clip retaining the
modulator. Draw the modulator off the valve.
12. Slacken the adjuster tube locknut. Rotate the
tube until the correct maximum pressure is
achieved. Tighten the locknut.
13. Rotate the minimum rate adjuster screw until
the correct minimum pressure is achieved.
14. Once the pressure has been set turn the
boiler off and disconnect the pressure gauge.
15. Tighten the pressure test screw and refit the
modulator to the valve. Reassemble in reverse
order.
Commissioning the Boiler
Checking the Burner Pressure
) will illuminate (Fig. 37).
). The
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