Technical data

6 720 611 445 GB (04.05)
24
Commissioning
To drain the appliance shut the system valves and open
the drain valve.
Suitable flushing agents and inhibitors are available
from Betz-Dearborn Tel: [phone] and Fernox
Tel: [phone]. Instructions for use are supplied
with the these products.
B Before commissioning, the gas supply pres-
sure must be checked at the gas supply pres-
sure test point (see page 6, fig. 2, item 7).
Natural gas appliances must not be operated if
the gas supply pressure is below 18 mbar or
above 24 mbar. LPG appliances must not be
operated if the supply pressure is not 37 mbar
at the inlet to the appliance.
B Unscrew the condensation trap (358) and pull out,
fill with approx. 1/4 l of water and refit. Refer to
fig. 31.
B Open all system radiator valves.
B Check the automatic air vent is open (27) see Fig. 31
B Turn on service valves (170), fill central heating sys-
tem.
B Vent radiators.
B Check that the gas type specified on the identifica-
tion plate matches that of the gas supply.
B Turn on gas cock (172). Refer to fig. 31.
B If a domestic hot water cylinder is fitted, set the hot
water cylinder thermostat to 60˚C.
5.2 Switching the appliance on/off
Switching on
B Switch on the appliance at the master switch (I).
The indicator lamp shows green and the display will
show the boiler flow temperature.
Fig. 32
The trap filling programme ensures that the condensa-
tion trap is filled after the appliance has been installed
or after the appliance has been out of use for a long
period or the mains supply has been interrupted. For
that reason, the appliance remains at minimum heating
output for 15 minutes.
Switching off the appliance
B Set the master switch to (0).
The green indicator lamp goes out.
5.3 Switching on the Boiler
The central heating flow temperature is adjustable
between 50˚C and 88˚C. refer to table 11, page 26.
B Turn the temperature control to set the flow temper-
ature to a level appropriate to the type of central
heating system:
– Low-temperature heating: setting “E”
(approx. 75˚C)
– Central heating systems for flow temperatures up
to 88 °C: limited “max” setting for low-tempera-
ture operation (see page 26).
When the burner is alight, the red indicator lamp
lights up.
Fig. 33
5.4 System controls
B Set room thermostat to the desired room tempera-
ture.
B Set time clock and the on/off periods. Refer to the
instructions with the control.
B Set the thermostatic radiator valves to the desired
settings.
i
If the display alternates between -II- and
the boiler flow temperature, the trap filling
programme is active.
6 720 610 333-04.1O
B Always disconnect the appliance from
the power supply (fuse, circuit breaker)
before carrying out any work on the
electrical systems or components.
6 720 611 137-12.1O