Worcester GR4700iW C Installation And Maintenance Instructions

Fault finding and diagnosis
Greenstar 4000 – 6 720 891 161 (2020/09)
76
2927 B Flame failed during burner operation No ionisation detected after ignition.
▶ Check the main shut-off valve, open if necessary.
▶ Check the appliance isolation valve, open if necessary.
▶ Measure the gas supply pressure at the rated heat input. If necessary, shut down the
appliance and check the gas line.
▶ Check flame sense electrode and connecting lead, replace if required.
▶ Check venturi/injector for potential blockage.
▶ Measure the ionisation current.
▶ Check the protective earth conductor connection (PE) in the control unit.
▶ Check the ignition cable for damage, replace if necessary.
▶ Check functionality of gas valve and replace if necessary.
▶Check CO
2
settings at min and max output
▶ Check flue system.
▶ Check combustion air supply.
▶ Check the heat exchanger on the flue gas side for deposits, clean if necessary.
2928 V Internal fault ▶ Restart appliance.
▶ If the fault persists following a reset, the burner control unit is faulty and must be
replaced, (replace control unit).
2931 V System fault boiler electronics / basic
controller
Illegal instruction.
▶ Restart appliance.
▶ If the fault persists following a reset, the burner control unit is faulty and must be
replaced, (replace control unit).
2940 V System fault burner control unit Low voltage.
▶ Restart appliance.
▶ If the fault persists following a reset, the burner control unit is faulty and must be
replaced, (replace control unit).
2946 V Incorrect code plug detected ▶ Check code plug, replace if necessary.
2948 B No flame signal with low output Burner starts automatically after purging. This can be caused by strong winds.
If this fault occurs frequently:
▶Check CO
2
settings.
▶ Check flue outlet position for effects of excessive wind pressure.
▶ Check flue integrity.
2949 B No flame signal with high output May be caused by strong winds or flue gas recirculation. The burner starts automatically
after purging.
▶ Check the flue integrity.
▶ Check the flue terminal position.
▶Check the CO
2
settings and adjust if necessary.
▶ Check the burner and the heat exchanger gaskets and the inner flue gaskets.
▶ Check the gas pressure during burning at full load (working pressure, dropping low).
2950 B No flame signal following starting procedure ▶ Check gas pressure whilst burning at full load.
▶Check CO
2
settings, adjust if necessary.
▶ Check Burner and heat exchanger gaskets.
▶ Burner restarts automatically after purging.
2951 V Loss of flame too many times Maximum unexpected flame losses exceeded.
▶ Refer to the blocking error(s) that lead to this locking error. Check the fault history on
appliance.
▶ Possible incomplete purging of gas pipe.
▶ Could also indicate a wide variety of issues such as undersized pipework or gas
pressure dropping off, incorrectly routed condensate discharge, incorrectly sited
flues, incorrectly wired etc.
2952 V Internal fault when testing the ionisation
signal
▶Perform reset.
▶ If fault persists, replace control unit.
2957 V Boiler electr. system fault ▶ Reset appliance electronics (factory reset).
▶ Check the electrical connections on the board (check for loose wires etc.).
▶ Replace the control unit.
Fault code Fault category
Fault text on the display, description Remedy

Worcester GR4700iW C Specifications

General

Brand	Worcester
Model	GR4700iW C
Category	Boiler
Language	English