Worcester CDi Combi N.G Service Booklet page 31

A6
and fault indicator LED are flashing. Appliance NOT available for demands.
External under floor heating thermostat defective.
Check
1. B Power OFF the appliance.
B Disconnect the appliance electrical
connection.
Check if the external under floor
heating thermostat is connected on
ST8/8-9?
2. B Disconnect lead to thermostat.
Check the thermostat for continuity?
3 B Unplug the harness connector that
connects the thermostat to the
control board.
Check the harness for continuity?
4 The control board is damaged.
Tab. 15 A6 Error codes
8 716 115 748 (2009/09)
Supplied By www.heating spares.co Tel. 0161 620 6677
Action
yes: go to 2
no: B Ensure that the link is securely connected to ST8/8-9
B Reconnect the appliance electrical connection.
B Power ON the appliance.
A6? go to 4
yes: B Reconnect lead to thermostat.
go to 3
no: B Change thermostat.
B Reconnect the lead to thermostat.
B Reconnect the appliance electrical connection.
B Turn the appliance ON.
A6? go to 4
yes A6? go to 4
no B Change or repair wiring to the thermostat.
B Reconnect the appliance electrical connection.
B Power ON the appliance.
A6? go to 4
B Reconnect the appliance electrical connection.
B Power ON the appliance.
B Make a note of the altered service function settings.
B Power OFF the appliance.
B Disconnect the appliance electrical connections.
B Change the control board.
B Reconnect the appliance electrical connection.
B Turn the appliance ON.
B Restore the service settings previously noted.
RECTIFYING FAULTS
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