Commissioning Of The Appliance; Regulating The Gas (Only For Authorised Technicians); Factory Regulation; Service Function - Bosch OptiFlow Professional GWH12 1 CTD E23 F3 OL Installation Manual

14 | Regulating the gas (only for authorised technicians)

If the power cable is damaged, it must be
replaced with a Bosch supplied spare part.
▶ Connect the power cable to a power socket.
5.2

Commissioning of the appliance

▶ Open the gas and water isolation valves and check the
tightness of all the connections.
If a controller is connected:
▶ place the ON/OFF button in the operating position.
The appliance is now ready to operate.
When a hot water tap is turned on, the passage of water
through the flow sensor (Fig. 2, [14]) 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, [13])
delivers gas to the burner.
• The burner ignites. Initially only one section of the burner is
lit, with remain sections igniting depending on the heat
required.
• The flame sensor rod (Fig. 2, [2]) detects the presence of
the flame.
• The temperature of the water is automatically adjusted by
the fan, gas and water valves.
Safety shut-down when the safety time is exceeded
If it is not possible to obtain the flame within the safety interval
stipulated, a safety shut-down is carried out.
The presence of air in the gas supply pipe (initial start-up of the
appliance or start-up after long periods of inactivity) may cause
a delay or difficulty when igniting.
If the ignition attempt is unsuccessful after a period of time, the
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-down
To put the appliance back into operation after a safety shut-off:
▶ Close all hot water taps.
6 720 810 559 (2016/06)
▶ Reset the appliance by switching it off at the socket and
unplugging the cord.
6 Regulating the gas (only for authorised
technicians)
6.1

Factory regulation

The data plate on the each appliance will show the factory
setting of that appliance.
Natural gas
The appliance must not be operated if the
dynamic connection pressure is less than
1.13 kPa or greater than 2.75 kPa.
Universal LPG
The appliance must not be operated if the
dynamic connection pressure is:
Universal LPG: less than 2.5 kPa or greater
than 4.5 kPa.
DANGER:
▶ The operations described below must only
be carried out by an authorised technician.
6.2

Service function

Accessing the service function
▶ Press and hold down at the same time
for 3 seconds.
Fig. 8 Service function
Display with indication "P2".
The service function is activated.
, and
6720806426-02.1V
OptiFlow Professional