Fault Codes; Locking Errors - Worcester 27i System Compact Installation, Commissioning And Servicing Instructions

FAULT FINDING AND DIAGNOSIS
7.5

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 code 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.
Maintenance These are displayed with the letter H followed by a number. The code advises of a situation that will need some attention but is not a
codes fault that will stop the boiler from functioning. Some of the common ones are listed:
H11 Hot water outlet sensor defect, hot water can still be delivered but with less control (sensor open/short circuit or out of position)
H13 A time has been set in the Service interval function i.e. 1 to 72 months and that time has expired. Menu 2.5F allows this feature to be
set (1 to 72), a 0 will disable this function.

LOCKING ERRORS

Cause
Fault codes codes Description
9A 362 HCM (Heat Control Module)
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 20 Locking fault and cause code listing
64
Reset type Possible cause
Reset button Incorrect HCM fitted
Reset button Problem with the code plug (faulty or not connected)
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 seconds
before this condition).
Reset button Sensor disconnected or damaged (the boiler will block for 300
seconds 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.
Greenstar i System Compact - 6 720 807 726 (2013/05)