www.johnsonandstarley.co.uk
23
6.1 Fault Codes
Cod
e
Fault
Reason
Action
N/A
Boiler will not run
No call for heat to boiler control
board
Check all external controls if fitted.
Check settings of the time clock.
Check settings of boiler controls
01
Flame lockout after several
ignition attempts
Flame not detected
Check gas supply and gas cock
If burner lights check flame sensor and wiring
to control board.
Check operation of gas valve
03
High water temperature
limit
Air in boiler. No water flow.
Vent boiler.
Check pump.
05
No tacho from fan
Fan not running or wiring fault
Check that fan runs.
Check wiring between control board and fan
07
High flue gas temperature Reduced water flow
Check pump operation.
08
Flame circuit error
Flame sensing lead shorted to
earth.
Check flame detection lead between sensing
probe and ignition control board.
09
Valve driver circuit error
Gas valve not detected
Replace ignition control board or gas valve
10-25 Internal control board fault
Replace main control board
26
Flame signal lost 5 times
in 4 minutes
Flame sensing error. Falling gas
pressure. Fan fault. Flue blockage.
Check flame detection lead between sensor
and ignition control board. Check gas supply:
does pressure fall when boiler fires?
Check that flue system is not blocked.
30
Boiler flow temperature
sensor short circuit
Temperature sensor shorted to earth
or failed.
Check wiring and connections for shorting to earth
Check sensor resistance
31
Boiler flow temperature
sensor open circuit
Temperature sensor not connected
or failed
Check wiring and connections.
Check sensor continuity
34
Low mains supply voltage
Electrical supply fault to property.
Faulty wiring to appliance
Check incoming mains supply and wiring to
appliance
35 &
36
Power supply fault
No fault on boiler
Boiler power supply should be checked by a
qualified electrician
37
Low system water pressure Water pressure low or sensor failed.
Check system pressure on dial gauge and if
correct check pressure sensor and wiring.
Re pressurize system.
39
Opentherm sensor (if fitted)
shorted to earth
Short circuit in wiring between sensor
and control board
Check wiring to sensor.
Check the electrical resistance of the sensor.
40
High system water pres-
sure
System water pressure too high.
Pressure sensor failed.
Check cold system pressure.
Check expansion tank charge pressure with sys-
tem pressure released. Check pressure sensor
43
Boiler return temperature
sensor short circuit
Temperature sensor shorted to earth
or failed
Check wiring and connections for shorting to earth
Check sensor resistance
44
Boiler return temperature
sensor open circuit
Temperature sensor not connected
or failed
Check wiring and connections
Check sensor continuity
45
Flue gas temperature sen-
sor short circuit
Short circuit in wiring between sensor
and control board
Check wiring to sensor
Check the electrical resistance of the sensor
46
Flue gas temperature sen-
sor open circuit
Temperature sensor not connected
or failed
Check wiring and connections
Check sensor continuity
