Potterton Performa 28i, Installation And Servicing Instructions, Page: 39 / 48

14.0 Fault Finding
39
Carry out initial fault finding checks
1. Check that gas, water and electrical supplies are available at the boiler. Electrical supply = 230V ~ 50 Hz.
CH water system pressurised to 0.5 bar when the boiler is cold. The preferred minimum gas pressure is 19.5mbar (natural gas), 27mbar
(butane) or 36mbar (propane).
2. Carry out electrical system checks, i.e. Ground Continuity, Resistance to Ground, Short Circuit and Polarity with a suitable meter.
NOTE: These checks must be repeated after any servicing or fault finding.
3. Ensure all external controls are calling for heat and check all external and internal fuses. Before any servicing or replacement of parts
ensure the gas and electrical supplies are isolated.
Refer to Section 13.0 “Illustrated Wiring Diagram” for position of numbered terminals
Domestic Hot Water - Preheating Function - Follow operational sequence
Turn On/Off/Reset selector
to position.
neon illuminated.
Turn preheat control to on.
Preheating function starts
after 25 seconds.
neon flashing.
Primary water diverted to
DHW preheating circuit.
Pump runs.
Primary flow switch
operated.
Fan runs at maximum
speed.
Air pressure switch proved.
Spark at ignition electrode
for up to 10 seconds.
Burner lights.
Burner output modulates to
minimum heat input until a
temperature of 75°C is
detected by central heating
NTC sensor.
Burner extinguishes.
Go to section ‘A’.
External controls and
where fitted, integral timer
calling for heat.
Go to section ‘L’.
Ensure controls are set to
demand and verify the
contacts are closed.
Go to section ‘M’.
neon flashing.
Go to section ‘B’.
neon flashing.
Go to section ‘C’.
neon flashing.
Turn the selector to reset.
neon flashing.
Go to section ‘D’.
Go to section ‘J’.
neon flashing.
Go to section ‘E’.
neon flashing.
Turn selector to the reset
position. If the neon does
not extinguish go to
sections H and K.
Change main PCB.
Burner extinguishes after
10 seconds.
Go to section ‘F’.
neon flashing.
Go to section ‘I’.
Go to section ‘G’.
Fan stops.
Pump continues to
run for 30 seconds.
Operation
sequence correct
YES
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
YES
NO
YES YES
YES
NO
YES
NO
YES
NOTE: When instructed to turn the Selector
to the reset position turn the Selector Switch
fully anticlockwise against the spring
pressure and hold for 2 seconds to reset the
boiler.