Potterton Performa 28i Installation And Servicing Instructions page 41

Central Heating - Follow operational sequence
Turn selector to
neon illuminated.
YES
Turn Central Heating
thermostat to maximum.
neon illuminated.
YES
Primary water is diverted
from preheating circuit to
CH system.
neon illuminated.
YES
Pump runs.
YES
Primary flow switch
operated.
YES
Fan runs at max speed.
YES
Air pressure switch proved.
YES
Spark at ignition electrodes
for up to 10 seconds.
YES
neon illuminated
YES
Burner extinguishes after
10 seconds.
NO
Preheating function starts
after 25 seconds.
neon flashing
(see DHW preheating
function).
YES
Primary water is diverted
from preheating circuit to
CH system.
neon illuminated
YES
Go to next page
NO
Go to section 'A'.
External controls calling for
NO
heat and where fitted,
internal clock calling for
heat.
NO
Go to section 'M'.
NO
neon flashing
Go to section 'B'.
NO
neon flashing
Go to section 'C'.
NO
neon flashing
NO
neon flashing
Go to section 'E'.
NO
neon flashing
NO
Go to section 'F'.
YES
neon flashing
Go to section 'I'
NO
Preheat control is not at
minimum position. External
control calling for heat.
NO
Go to section 'M'.
14.0 Fault Finding
Ensure controls are set to
NO
demand and verify the
contacts are closed.
YES
neon flashing
Go to section 'B'.
Turn the selector to reset.
If regular resetting is
YES
required or appliance still
does not operate
investigation is necessary.
NO
neons flashing
Go to section 'D'.
YES
NO
Change main PCB.
Go to section 'L'.
Go to section 'J'.
Turn selector to the reset
position. If the neon does
not extinguish go to
sections H and K.
41