Electrical Connection (Only By Authorised Technicians); Connecting The Power Cable; Commissioning Of The Appliance; Changing The Setpoint Limit Temperature (Only For 55 °C Preset Appliances) - Bosch Optiflow Professional GWH12 Installation Manual

16 | Installation (only by an authorised technicians)
4.10 Electrical connection (only by authorised
technicians)
DANGER: Due to electric shock!
▶ Before carrying out work on electrical
components, disconnect the power
supply (230 V AC) (by isolating switch
and removing the power plug from the
electrical socket) secure against
unintentional reconnection.
All the regulating, control and safety devices in the appliance
are factory supplied already connected and ready to operate.

4.10.1 Connecting the power cable

The electrical connection must be done in
accordance with AS/NZS3000.
If the power cable is damaged, it must be
replaced with a Bosch supplied spare part.
▶ Connect the power cable to a power socket.

4.11 Commissioning of the appliance

▶ Open the gas and water isolation valves and check the
tightness of all the connections.
When a hot water tap is turned on, the movement of water
through the flow sensor (fig. 2, [15]) sends a signal to the
control box. This signal triggers the following actions:
• The fan to start working.
• The ignition sequence and the gas valve (fig. 2, [18])
delivers gas to the burner.
• The burner ignites. Initially only a part of the burner is lit.
• The flame sensor rod (fig. 2, [2]) detects the flame.
• The temperature of the water is checked automatically by
the sensors. The appliance adjusts the gas flow and water
flow to achieve the temperature selected.
• Depending on the output required, the rest of the burner
will ignite.
Safety shut-down when the safety time is exceeded
If the appliance does not maintain a flame within the safety
interval stipulated, a safety shut-off is carried out.
Air in the gas supply line may cause a delay or difficulty when
igniting.
If the ignition attempt is unsuccessful after a period of time, the
6 720 810 560 (2016/06)
safety devices block the operation of the appliance, and air will
have to be purged from the circuit.
Safety shut-down due to an excessively high water
temperature
The electronic control unit detects the temperature of the
water through the thermistor placed at the hot water outlet. If
the appliance detects an excessive temperature, a safety
shutoff will occur.
Safety shut-off due to incorrect flue conditions
If the appliance detects an incorrect flue condition, a safety
shut-off will occur.
Re-start after a safety shut-off
To put the appliance back into operation after a safety shut-off:
▶ Close all hot water taps.
▶ Reset the appliance by switching it off at the socket and
unplugging the cord.
4.12 Changing the setpoint limit temperature
(only for 55 °C preset appliances)
The maximum temperature is preset to 55 °C. If required it can
be increased to 60 °C or 70 °C.
▶ Enter the Service function (section 5.2).
Display will show "P2".
▶ Press until the display shows "P4".
▶ Press the button .
Display will show "E".
▶ Press until the display shows "SL".
▶ Press the button .
Display will show "55"
▶ Press until the display shows "60" or "70".
▶ Press the button
The value flashes to confirm the new setpoint limit.

4.13 Delivery temperature calibration

If the delivery temperature at the closest hot water outlet to the
appliance does not match the setpoint it can be adjusted as
follows:
▶ Enter the Service function (section 5.2).
Display will show "P2".
▶ Press until the display shows "P4".
▶ Press the button .
Display will show "E".
▶ Press until the display shows "SC".
▶ Press the button .
Display will show "0"
▶ Press or to adjust the delivery temperature as
required.
The setpoint can be adjusted between -5 °C and +5 °C.
for 3 seconds.
Optiflow Professional