Vallox 75, Instructions For Use And Maintenance Manual

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Vallox Oy FIN-32200 Loimaa Finland Tel358 2 7636 300 Fax +358 2 7631 539
www.vallox.com
VALLOX 75/95
TROUBLESHOOTING
2. Other possible disturbances
1. Outdoor air coming to the dwelling is cold.
In case of failure in a block of flats or terraced house, contact the person responsible for maintenance or
a maintenance company.
• Outdoor air fan stops at too high outdoor temperatures.
• Both fans of the VKL model have stopped.
DO THIS
• If the fan keeps stopping at too high outdoor temperatures, check the operation of the defrost thermostat. The function
starts as soon as outdoor temperature goes below -10 ° C. The threshold is not absolute, but is dependent on the length
of the ductworks, insulation, the speed of the unit and other things.
• If both fans of the VKL model have stopped, the defrost function of water-operated radiator is active.
NOTE! If there is no non-freezing solution in the water of the radiator, the radiator is at risk of freezing and breaking
down. If the radiator breaks down, there is a risk of water damage. Immediately troubleshoot the situation. Check if
the circulation pump is broken, the boiler out of operation, etc. The situation may go return to normal by itself as soon
as supply air temperature rises over 10 ° C, but do not wait till it happens.
You can influence the operation of the defrost thermostat as follows:
• If freezing occurs in the cell, you can put the sensor closer to the cell, which makes the fan stop earlier (the cell has to
be thawed out before closing the lid).
• If the fan keeps stopping at too high outdoor temperatures (no humidity, no freezing), you can move the sensor further
away from the cell.
• An expert may also adjust the thermostat in the connection box by turning its spindle clockwise to +10 ° C or counter-
clockwise to 0 ° C. At 0 ° C freezing is unlikely; at 10 ° C no freezing occurs but extract air can be too warm when going
out. According to the factory setting, the defrost thermostat works at 4 ° C.
• Air cools down in the attic ducts.
• The heat recovery cell is frozen, which is why extract air cannot heat outdoor air.
• The post-heating radiator does not work.
• The extract air filter or cell is clogged.
• The initial adjustment of ventilation has not been done.
DO THIS
• Measure the temperature of supply air in the unit and compare it with the air coming from the valve. If air cools down
in the duct, check the insulation of the attic ducts.
• If the electric radiator does not heat up, check if the adjustment thermostat is in the desired position. (change the setting
if needed) or if overheat protection has tripped (press the black button at the end of the radiator). If the protector has
tripped, you hear a click when pressing the button. Pressing the button resets the radiator in working order after the
tripping of the overheat protector. Consult an expert to find out why the overheat protector tripped. If the water radiator
of the VKL model does not heat up, there might be many reasons for this: e.g. wrong position of thermostat; water does
not circulate in the radiator; pump may be stopped or some of the valves off; water circulating in the radiator may be
cold, etc. If necessary, consult an expert.
• If a filter or cell is clogged, clean it (see the instructions).
• If the initial adjustment has not been done, have it done.
• If the cell is frozen, check the operation of the defrost thermostat.
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