Fault finding and diagnosis
73
Greenstar 2000 – 6 721 820 552 (2021/02)
11
Fault finding and diagnosis
This fault finding information is for guidance only. Worcester cannot be
held responsible for costs incurred by persons not deemed to be
competent.
This fault finding system assumes that the appliance has been operating
normally until the time of failure (i.e. not a first time installation error).
Basic checks
• Ensure that there is 230V power supply and the polarity is correct to
the appliance.
• Ensure that the appliance settings and functionality is correct.
• Ensure the CH/DHW programmer/timer is functioning.
• Ensure the room thermostat is functioning.
• Ensure the cylinder thermostat (if fitted) is functioning.
• Ensure the cold water mains is turned on.
• Ensure the primary system has adequate pressure/system content
for the system type.
• Ensure there is gas to the appliance.
– Are other gas appliances working, gas cooker/hob for example?
– Has the credit run out on the gas pre-payment meter?
NOTICE
On completion of the Service/Fault-Finding task which has required the
breaking and remaking of electrical connections, check:
▶ Earth continuity,
▶ Short circuit check,
▶ Polarity,
▶ Resistance to earth.
11.1
General information
Indicators (fault category O)
Indicators signal operating conditions during normal operation.
Indicators can be read out with the service function 1-A1.
Non-blocking faults (fault category R)
The heating system remains in operation with non-blocking faults. The
H
symbol is shown on the display.
Fig. 105 Example: non-blocking fault
Resetting a non-blocking fault
▶ Press the
"
key until the
H
and
!
symbols are displayed.
The fault code with the smallest number is displayed.
▶ To select a fault code: press arrow key
or
.
▶ To delete the fault code: press the
OK
key.
▶ Follow the same procedure to delete further fault codes.
Blocking faults (fault category B)
Blocking faults result in the heating system being shut down temporarily.
The heating system restarts automatically as soon as the blocking fault is
removed.
If the blocking fault persists for a prolonged period, it becomes a locking
fault.
The fault code of a blocking fault can be read out with the service
function 1-A2.
Locking faults (fault category V)
Locking faults result in the heating system being shut down, and the
system can only be restarted after a reset.
The fault code of a locking fault flashes together with the
H
on the
display.
▶ Turn the power to the boiler off and on again.
-or-
▶ Press the arrow keys
and
at the same time until the symbols
H
and
!
disappear.
The device resumes operation. The flow temperature is displayed.
If a fault persists:
▶ Check PCB, replace if required.
▶ Adjust the service functions as directed on the “Settings in the
service menu” label.
Blocking into Locking faults (B/V)
If the blocking fault persists for a prolonged period, it becomes a locking
fault.
Fault category W (maintenance codes)
0010016301-001
