16
GB-031C/f.347
FAULT FINDING
Symptom
Reason
Procedure
The indicators and LCD display
on the front panel are off
No power to the boiler
Check electricity mains power supply
Main over heat stat cut-out
Check the temperature safety cut-out investigate cause
- possibly fault / return sensors or power board
The “A” indicator flickering
Insufficient water pressure
Check water pressure in display panel and increase to 1.5 bar
Pressure Sensor failure
Check water pressure in display panel and if display shows
“- - “ then replace Pressure Sensor
The “H” indicator flickering
Pump is blocked
Free Pump by setting the Pump on the highest gearing – See
Figure 3 then unscrew the screw on the Pump housing –
See Figure 2. Move Pump rotor manually.
Water is not circulating through the
Boiler
Vent the system: Radiators, Pump and Boiler
Pump not running
Check power available at Pump head, if power available
replace as necessary. If power not available check fuse on
Controller Module and replace if necessary
Flow sensor not operating
Check the flow sensor and replace as necessary
‘G’ indicator is flashing but boiler
digital display operating
’NA’ connection open circuit
Ensure ‘NA’ connection is closed or if using external control
(e.g. Shower Sensor) that this is working correctly
‘G’ indicator flashing
‘NA’ connection open circuit
Check ‘NA’ connection - should be closed
‘K’ indicator flickers
Failure of inlet temp sensor
Replace inlet temp sensor
‘L’ indicator flickers
Failure of outlet temp sensor
Replace outlet temp sensor
‘G’ ‘H’ & ‘K’ Indicators lit but
boiler not heating
No supply to heating coils from
Power Board.
Check outputs ‘G1’ ‘G2’ & ‘G3’ on Power Board if 230Volts
not present to all replace Power Board
‘G’ ‘H’ & ‘K’ Indicators lit but
boiler only partially heating
One or more heating coils have no
voltage supply from Power Board
Check outputs ‘G1’ ‘G2’ & ‘G3’ on Power Board if 230Volts
not present to all replace Power Board
