58
Once the required diagnostic code is
displayed the right hand button
(1, fig. 107) should be pressed; this
will instruct the microprocessor to
carry out that particular check.
To return from a diagnostic enquiry,
depress the right button (1, fig. 107)
once more.
You can now carry out a further diag-
nostic check (as described above) or
exit back to the normal mode by de-
pressing both buttons simultaneously.
(See Section 8.3: `Fault diagnosis
using the boiler fault mode' for further
details).
4. Status Mode
The boiler display may also be used
to show the current status of the boiler
in its operating cycle.
To display the status mode depress the
right button (1, fig. 107) once, e.g.
boiler display showing status code
S.4 - fig. 109.
The status mode is helpful in diagnos-
ing faults where a fault code is not
displayed. (See Section 8.4: `Fault
diagnosis using the boiler status
mode' for further details)
8.2 Logical fault finding
procedure
8.2.1 Preliminary Checks
These checks must be carried out be-
fore attempting to use the fault finding
guide:-
1) Carry out electrical safety checks
(see Section 5.1: Preliminary elec-
trical checks).
2) Check that the external electricity
supply to the boiler is on, and a
supply of 230V~ is present
between boiler terminals 'L' and
'N'.
3) Check that gas supply to the boiler
is on and that it has been correctly
purged
(see Section 5.2: Gas Supply).
fig. 109
GW 505/0
