VALLOX 252 D
5
INSTRUCTIONS FOR USE
Control panel
Service reminder
• The maintenance reminder switches on the maintenance reminder symbol ( ) in
the control panel at defined intervals, the factory setting being 4 months.
• The maintenance reminder symbol is acknowledged at the main display of the
control panel (see the instructions for using the control panel, Section 1.3.7.).
• The interval may be set between 1 and 15 months on the control panel.
Supply air constant temperature control
• The basic setting for supply air temperature control is constant temperature
control.
• The aim is to permanently keep the temperature of air blown to the ventilation
zone within the range +10...+30˚C.
• Temperature control is only active when post-heating has been switched on.
Supply air cascade control
• Supply air temperature control can be replaced with cascade control.
• Cascade control changes the mode of regulating the post-heating radiator: the
temperature of air blown to the ventilation zone is controlled on the basis of
extract air.
• Temperature is controlled on the basis of the difference between the setpoint and
the actual temperature. For instance, if indoor air temperature is 25˚C and the
setpoint is 24˚C, the aim is to blow 23˚C air to the ventilation zone. If the
temperature in the ventilation zone is 24˚C and the setpoint is 25˚C, the aim is to
blow 26˚C air to the ventilation zone.
• The aim is to permanently keep the temperature of air blown to the ventilation
zone within the range +10...+30˚C.
• Cascade control can be chosen on the control panel, and it is active when post-
heating has been switched on.
Fireplace switch / boosting function
• The booster switch raises fan speed to the preset maximum fan speed for 45
minutes.
• The fireplace switch stops the extract air fan for 15 minutes and causes
overpressure in the ventilation zone. This facilitates lighting up the fireplace, for
instance.
NOTE! When the extract air fan starts, the draft in the fireplace may stop.
• The function is selected on the control panel.
Fault signalling relay
• The fault signalling relay has potential free points (24VDC, 1A).
• The points provide information on failure modes of the ventilation unit.
• During water radiator defrosting, the points of the relay close and open at 10-
second intervals.
• High carbon dioxide content alarm switches the relay every second.
• In other failure situations, the points are closed.
