Fault Finding; Troubleshooting; Faults That Are Displayed - Worcester GREENSTAR 24 Installation, Commissioning And Servicing Instructions

Fault finding

Special
display Description
The display shows the flow temperature alternating with
. The appliance operates for 15 minutes at the
minimum rated output.
The display shows the flow temperature alternating with
. The appliance operates with the set maximum rated
output in central heating mode,  service function 1.A.
The display shows the flow temperature alternating with
. The appliance
operates for 15 minutes at the maximum rated output.
Vent function active, see service function 2.C.
The display shows the flow temperature alternating with
. The syphon fill program is active,  service
function 4.F.
Table 29 Special displays
12.2

FAULTS THAT ARE DISPLAYED

Display
A7 DHW temperature sensor faulty.
A8 Communication fault.
Ad Cylinder temperature sensor not detected.
b1 Code plug not detected.
b2 Internal data error.
b3
C6 Fan not running.
CC Outside temperature sensor not detected.
d3 External limiter has tripped.
d5 External primary NTC on low loss header defect.
E2 Temperature sensor in CH flow faulty.
E9 Heat exchanger temperature limiter or flue gas
temperature limiter has tripped.
or
Flue pipe is blocked.
EA Flame not detected.
F0 Internal fault.
F1 Internal data error.
F7 A flame is detected although the appliance is switched off. Check electrodes. Flue system OK? Check PCB for moisture.
FA A flame is detected after the gas has been switched off.
Fd Reset was pressed in error.
Table 30 Displayed faults
48
Special
display Description
The display shows the flow temperature alternating with
: the set inspection interval has elapsed,  service
function 5.A.
The display shows the flow temperature alternating with
. The heating circuit pump is blocked.
The display shows the flow temperature alternating with
. The temperature gradient limiter is enabled.
Excessive flow temperature increase: central heating
mode is suspended for two minutes.
Screed drying function of the weather-compensated
controller ( operating instructions) or building drying
function ( service function 7.E) operational.
Key lock enabled. To reset the key lock, press
the flow temperature is shown on the display.
Table 29 Special displays
Remedy
Check the temperature sensor and connecting lead for breaks or short circuits.
Check BUS device connecting lead.
Check cylinder temperature sensor and connecting lead.
Insert code plug correctly, test and replace if necessary.
See servicing instructions for heating contractors.
Check fan lead and connector, check fan, replace as necessary.
Check outside temperature sensor and connecting lead for breaks.
Temperature limiter TB1 has tripped. Jumper across 8-9 or PR-P0 is missing.
Check NTC and cable continuity.
Check the temperature sensor and connecting lead.
Check system pressure, temperature limiter, pump operation, fuse on PCB bleed
appliance. Check water-side of heat exchanger. On appliances with displacement
bodies in heat exchanger, check whether displacement bodies are fitted. Check
the flue (fresh air or exhaust gas) pipe blockage, check air pressure switch and air
pressure switch pipe. Check heat exchanger high limit stat and flue high limit stat.
Is gas tap open? Check gas supply pressure, mains power connection, electrodes
and leads, flue pipe, gas-air ratio.
12 FAULT FINDING
On natural gas appliances, check external gas flow switch.
Check electrical connectors and ignition leads, replace PCB if necessary. Check
gas-air ratio.
See servicing instructions for heating contractors.
Check gas valve. Clean condensate trap and check electrodes. Flue system OK?
Press reset again.
until
6 720 811 922 (2014/07)