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© VALLOX • We reserve the right to make changes without prior notice.
What the units include can vary depending on the sales area.
Vallox
121
SE
OPERATING INSTRUCTIONS
Adjustment of supply air temperature
and summer/winter function
The temperature of air coming to the dwelling can be adjusted
between circa +10 °C and +30 °C. When there is a light on the
post-heating indicator, post-heating is activated and the unit heats air
as needed. The need for heating depends on the setpoint of supply
air temperature.
When there is no light on the post-heating indicator, post-heating is
off. This means that summer function is activated for the ventilation
unit. The unit has a motorised summer/winter function. When the
summer function is on, the heat recovery cell is bypassed as soon
as outdoor air temperature has risen above the setpoint. See the
setpoint for cell bypass, factory s12 ºC. When outdoor air
temperature goes below the setpoint (factory s12 °C), the unit
starts to recover heat. If there is water-circulating post-heating in the
unit, supply air fi nds the desired value very slowly. It takes hours for
the unit to reach the correct setpoint. The amount of time depends on
the temperature of the fl uid circulating in the post-heating radiator.
Two different kinds of supply air temperature adjustment can be
chosen at the unit: constant temperature control or cascade control.
In constant temperature control, the unit controls the temperature of
supply air directly in accordance with the measurement information
on the temperature of supply air blown to the ventilation area. In
cascade control, the unit controls supply air temperature according
to the temperature of air extracted from the ventilation area. The unit
calculates the difference between the air extracted and the setpoint
for supply air and uses this difference to control the need for post-
heating.
Winter function of ventilation unit
A set of parameters has been set at the factory for the freezing of
the heat recovery cell. When these parameters are undercut, the
ventilation unit start to melt the heat recovery cell. Melting is done by
stopping the supply air fan. A normal melting period takes from 15 to
45 minutes depending on the extent of ice on the heat recovery cell
and on the amount of extract air fl ow. The unit operates optimally on
the factory settings in normal operation in dwellings and detached
houses. The parameters only need to be touched in extreme problem
situations. Examples of such situations are high humidity loads such
as a swimming pool or a situation where the exhaust air duct has
frozen through.
Remember!
Switch post-heating off when it starts to get too warm in the
dwelling because of warm weather.
Switch post-heating on again when it gets cooler in autumn.
Post-heating indicator light
Maintenance reminder
symbol
Maintenance reminder
• The maintenance reminder switches on the maintenance re-
minder symbol ( ) in the control panel at defi ned intervals,
the factory setting being 4 months.
• The maintenance reminder symbol is reset at the main
display of the control panel (see the operating instructions
for the control panel, Section 3.1.).
• The interval can be set between 1 and 15 months at the
control panel.
Fireplace switch function/boosting
Fireplace switch function
• The fi replace switch stops the extract air fan for 15 minutes and
produces overpressure in the ventilation zone. This makes it
easier to light a fi replace.
• The function is started on the main display of the control panel
by simultaneously pressing and holding down the + and - but-
tons for 2 seconds.
• The function can also be started at a separate auto-reset push-
button switch, wired from the connection box of the unit for
example to a wall in the fi replace room. Upon each pressing,
the stopping function continues for 15 minutes (the switch is not
included in the delivery).
• During the function, the fi replace/booster switch symbol ( ) is
visible in the main display of the control panel.
Boosting switch function
• The booster switch function raises fan speed to the set maximum
fan speed for 45 minutes.
The function is started on the main display of the control panel
by simultaneously pressing and holding down the + and – but-
tons for 2 seconds.
• The function can also be started at a separate auto-reset push-
button switch, wired from the connection box of the unit to
for instance a wall in a classroom. Upon each pressing, the
boosting function continues for 45 minutes.
• During the function, the fi replace/booster switch symbol ( ) is
visible in the main display of the control panel.
• The function is chosen at the control panel.
Fireplace/
booster switch
symbol
Fault signal relay (remote monitoring)
• The fault signal relay has potential-free contacts (24 VDC,
1 A).
• The contacts provide information on various failure modes
of the unit.
• Alarm of high carbon dioxide content switches the relay at
1-second intervals.
• In other fault situations, the contacts are closed.
NOTE! The starting of
the extract air fan may
weaken draught in the
fi replace! In winter, this
situation may disturb
the winter function of
the unit. The situation
will normalise in a
while, after the fi replace
function stops.
