Fault Code Table - Worcester Greenstar 2000 Installation And Maintenance Instructions Manual

Fault finding and diagnosis
11.2

Fault code table

Description
200 O Boiler in heating mode
201 O Boiler in hot water mode
202 O Boiler in anti-cycle mode
203 O Boiler in standby, no heat energy demand
204 O Current prim. water temp. higher than set
val.
208 O Chimney sweep demand
212 – Rise in temp. of safety or heating flow
sensor too fast
214 V Fan shut down during safety time
215 V Fan shut down during safety time
224 B/V Safety temp. limiter has tripped
227 B/V No flame signal after ignition
228 V Flame signal without flame present
229 B Flame failed during burner operation
74
Remedy
Operating message, is not a fault.
Operating message, is not a fault.
Operating message, is not a fault.
Operating message, is not a fault.
The actual boiler water temperature is higher than the target boiler water temperature. The
boiler is switched off.
Operating message, is not a fault.
Open the shut-off valves.
▶ Reset the appliance.
▶ Create a heat demand; check if the boiler fires up.
▶ Check the voltage to the fan and the continuity of the fan harness.
▶ Check the power modulation on the fan.
▶ PCB may be defective.
▶ Replace fan.
▶ Mains voltage must correspond to the default value.
▶ Check PCB and fan harness, replace if necessary.
▶ Check if lead is disconnected from the safety temperature limiter.
▶ Check the high limit of the safety temperature limiter and the harness for continuity.
▶ Check the flow temperature to confirm actual temperature (may have tripped out at
lower temperature, leading to safety temperature limiter fault)
▶ Check the system pressure and top up as required.
▶ Check if air is trapped in the system and in the boiler.
▶ Pump seized/not running: check the pump for failure or blockage.
▶ Check if blockage/restriction within boiler/pipe work restricting the flow.
Tip: Check the ceramic insulator is not damaged, this can cause the spark to earth, twist
and pull the ceramic insulator to ensure it is not broken.
▶ Check the gas supply to property and the inlet on the gas valve.
▶ Check the low pressure when the gas valve opens.
▶ Gas valve failing to open: check for voltage to the valve and for possible blockage on
inlet filter of the gas valve.
▶ Obstruction in the air intake to the fan leading to incorrect CO
damaged or stuck.
▶ Condensate trap is blocked or restricted. Condensate pipe is frozen.
▶ Flue is blocked or restricted.
▶ Heat exchanger is blocked or restricted.
▶ Check the burner for damage.
▶ Check the spark electrode or the lead failure.
▶ Check the flame sense or the lead failure.
▶ Check the rectification ground (black wire to heat exchanger).
Tip: Check the ceramic insulator is not damaged, this can cause the spark to earth, twist
and pull the ceramic insulator to ensure it is not broken.
▶ Check the flame sense and the lead and replace if required.
▶ Check the earth tags on the boiler and on the electrodes.
▶ Check the operation of the siphon and no water collecting in the sump.
▶ Replace the air and/or gas ratio control valve.
▶ Replace the control unit and/or burner control unit.
Tip: Check the ceramic insulator is not damaged, this can cause the spark to earth, twist
and pull the ceramic insulator to ensure it is not broken.
▶ Check the gas supply to the property and check the working pressure on the gas valve
inlet.
▶ Check the gas-air ratio.
▶ Check the ionisation electrode and the harness for damage or contamination.
▶ LPG: Sufficient gas in the tank or recently refilled?
ratio. Diaphragm is
2
Greenstar 2000 – 6 721 820 552 (2021/02)