Fault Codes - Worcester Greenstar CDi Compact Installation, Commissioning And Servicing Instructions

7.6

FAULT CODES

Should a fault develop with this boiler (or the system), the boiler will
enter a locking or blocking condition, and fault code information will be
generated as described in this section.
Locking error The boiler display will flash a warning triangle and fault code. At the same time a (static) cause code will also be displayed.
Manual intervention is required following clearance of the fault:
▶ Press the reset button on the boiler fascia
Blocking error The boiler will stop operating with no fault data displayed. The cause code, in the info menu, is accessed by pressing the
spanner/return button. The condition will clear automatically when the associated fault clears e.g. waiting for an area to cool.
In some cases a blocking error has a defined time duration prior to changing to a locking condition.
Fault code Alpha numeric number indicating the fault group
Cause code Three digit number. During a blocking error (or normal operating status) it is not displayed, but accessed in the info menu via
the spanner/return button. During a locking error the cause code flashes on the display.
LOCKING ERRORS
Cause
Fault codes codes Description
9U 233 HCM (Heat Control Module)
b7 257 Internal error
C6 215 Fan problem
216 Fan problem
C7 214 Fan problem
217 No airflow after a defined
period of time
D1 240 Return sensor error
241 Return sensor error
286 Return temperature too high
E2 222 Flow sensor short circuit
223 Flow sensor open circuit
E5 218 Flow temperature too high
332 Primary flow sensor has
exceeded 110°C
E9 219 Safety sensor temperature too
high
220 Safety sensor short circuit
221 Safety sensor open circuit
224 Max temperature thermostat
activated
EA 227 No flame detected after
ignition
229 Loss of flame signal during
operation
234 Gas valve error
261 Ignition timing error
Table 21 Locking fault and cause code listing
6 720 803 800 (2012/11)
Reset type Possible cause
Reset button Problem with the code plug
Replace control board.
Reset button Fan running too fast
Reset button Fan running too slow
Reset button Fan not running
Reset button Fan not running or airflow blocked
Reset button Sensor wet or damaged (the boiler will block for 300 secs before this
condition).
Reset button Sensor disconnected or damaged (the boiler will block for 300 secs
before this condition).
Reset button Boiler overheat
Reset button Flow sensor shorted or damaged.
Reset button Flow sensor disconnected or damaged.
Reset button Primary flow sensor overheated
Reset button Primary flow sensor overheated
Reset button The main heat exchanger has overheated.
Maximum temperature 105C°
Reset button Maximum temperature sensor on the main heat exchanger has failed.
Reset button Maximum temperature sensor on the main heat exchanger has not
been recognised.
Reset button Flue gas thermostat overheat
Reset button Failure of four ignition attempts. The boiler waits 30 seconds before
another attempt is made.
Reset button An established flame has been extinguished.
This could be caused by:
• moisture in the sump, due to a blocked sump/condensate trap.
• a strong wind into the flue.
Reset button Gas valve coil disconnected
Reset button Flame not established during the first 4 seconds ignition period.
FAULT FINDING AND DIAGNOSIS
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