17
24/28/bi
24/28/bi
24/28/bi
24/28/bi
24/28/bi
If tests on the isolator also reveal reversed polar-
ity or a supply fault, consult the local electricity
supplier for advice.
7.7.5
RESISTANCE TO EARTH CHECK
Isolate the appliance from the electrical supply,
and using a suitable multi-meter carry out a
resistance test. Connect test leads between the
Live & Earth connections at the appliance termi-
nal strip (fig.16). If the meter reads other than
infinity there is a fault that must be isolated, carry
out a detailed continuity check to identify the
location of the fault.
7.8
FAULT FINDING
Before attempting any faultfinding, the electrical
checks as detailed in 7.7 must be carried out.
Isolate the appliance from the electrical supply.
Disconnect any external controls such as room
thermostats etc. from the boiler.
7.8.1
REPLACING THE MAIN PCB
When replacing the main PCB it’s essential
that the potentiometers are set as follows
:
●
P4
- set at minimum
●
P5
- set at maximum.
EFFECT OF JUMPER TAGS FITTED TO THE
MAIN PCB AT:
●
JP1
- Rain/Rain bi boiler
●
JP2
- cancels anti-cycle function and initial
heating output (75% of maximum at start up)
●
JP3
- for LPG boilers only
●
JP4
- N/A.
NOTE
Restore the electrical supply to the boiler and turn
the selector switch to the on position. The boiler
should now function as described in section 7.2.
Should the boiler fail to respond, the internal
fuses and connectors should be checked to
ensure integrity and continuity. If the boiler still
fails to respond, refer to the detailed faultfinding
flowcharts overleaf.
IMPORTANT
These series of checks must be carried out
before attempting any fault-finding procedures
on the appliance. On completion of any task that
required the disconnection and re-connection of
any electrical wiring or component, these checks
must be repeated
.
7.9
FAULT CODES
When the boiler is in a fault condition, the LED is
displayed in a colour and/or frequency that is
relevant to the fault. To reset the boiler, turn the
mode selector switch to the reset position for 2-
minutes’ then back to the relevant mode of opera-
tion.
If the boiler does not reset, refer to the following
section and the detailed faultfinding flowcharts
overleaf.
Frequency
Faults/Status
Solid
Check JP1
YELLOW LED
Frequency
Faults/Status
On every 0.5-secs
Final fault, e.g.:
●
●
●
●
●
primary NTC
●
●
●
●
●
water pressure
●
●
●
●
●
fan/flue problem
●
●
●
●
●
ignition/lockout problem
Solid
Limit thermostat
RED LED
