37
ecoTEC plus 937 installation and maintenance manual
5.5
Initial flushing of the system ("cold“)
h
Note!
The entire heating system must be flushed
through completely at least twice: once cold
and once hot, in accordance with the following
instructions.
• Check if all radiator thermostat valves and both
isolation valves on the combi boiler are open.
• Connect a hose to the drain valve which is located at
the lowest position in the heating system.
• Open the 1/2“ drain valves and all the bleed valves on
the radiators so that the water flows quickly and
completely out of the heating system and the combi
boiler, in order to remove the contamination caused
during the installation out of the heating system
before the combi boiler is started up.
• Close the 1/2” drain valves and radiator bleed vavles.
• Re-fill the heating system with water as described in
Section 5.4.3.
• Check that the pressure relief valve in the heating
system is functioning correctly by turning the handle
on the valve.
• Check the pressure in the heating system and top up
with water if necessary.
• Close the filling loop valve and the cold water isolation
valve.
5.6
Filling the condensate siphon
1
Fig.5.4 Filling the condensate siphon
d
Danger!
If the condensate siphon is empty during
operation of the combi boiler there is a danger
that exhaust gases can flow into the room and
cause poisoning. For this reason you must make
sure that the siphon is filled up every time the
unit is cleaned.
• Remove the lower section (
1
) of the condensate siphon
by turning the bayonet connection in a
counterclockwise direction a quarter of a turn.
• Fill the lower section with water until about 10 mm
below the upper edge.
• Replace the lower section of the condensate siphon.
5.7
Setting the pump output
Only in ecoTEC plus appliances:
The output of the two-speed pump can be matched to
the requirements of the heating system. If required,
change the pump output, depending upon the setting of
the operating mode, under diagnostic number "d.19“
(see Section 8.1.2).
5.8 Adjusting
the
bypass
The appliance is equipped with an adjustable bypass
valve. The pressure can be set between 170 and
350 mbar. The valve is pre-set to approx. 250 mbar (mid-
position). Each turn of the setting screw changes the
pressure by approx. 10 mbar. The pressure is increased
by turning to the right and reduced by turning to the
left.
1
Fig. 5.5 Setting the bypass valve
• Setting the by-pass valve using the setting screw (1).
Commissioning, Part I 5
