Bosch OptiFlow Professional GWH12 1 CTD E23, Operating Manual

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6 720 813 939 (2016/05) OptiFlow Professional
10 | Troubleshooting
E2 Faulty inlet water temperature sensor. ▶ Check temperature sensor and associated
connections.
▶ If the problem persists, call an authorised
service technician.
E4 Air temperature sensor detects overheating (leaking
combustion products inside the combustion
chamber). ▶ Switch off at the power point and remove
the plug from the electrical socket.
▶ Do not try to Restart the appliance.
▶ Call a service agent immediately.
E9 Activated thermal fuse. ▶ Call an authorised service technician.
EA Flame not detected. ▶ Check that the gas to the appliance has not
been turned off.
▶ Unplug the electrical connection for 10
seconds.
▶ Reconnect and restart the appliance.
▶ If the problem persists, call an authorised
service technician.
EE Modulating solenoid valve disconnected. ▶ Check solenoid connections.
▶ If the problem persists, call an authorised
service technician.
EF Wrong gas connected. ▶ Call an authorised service technician.
F7 A flame is detected although the appliance is
switched off. ▶ Unplug the electrical connection for 10
seconds.
▶ Reconnect and restart the appliance.
▶ If the problem persists, call an authorised
service technician.
F9 Safety solenoid valve disconnected. ▶ Call an authorised service technician.
FA Fault in the gas control valve. ▶ Call an authorised service technician.
FC Buttons stuck in a “pressed” position for more than
30 seconds. ▶ Release the button.
▶ If the problem persists, call an authorised
service technician.
With indication,
but without existence of
solar thermal system.
The temperature selected is lower than the minimum
power that the appliance supplies.
High incoming water temperatures, or low flow rate
can create this occurrence.
▶ Increase the hot water flow.
-or-
▶ Select a higher temperature.
▶ If the problem persists:
▶ Call an authorised service technician.
With indication
and water temperature
low.
Appliance is making a resonance noise (vibration). ▶ Call an authorised service technician.
Display Description Possible solution
Table 4