
Vallox Oy • Myllykyläntie 9-11 • FI-32200 Loimaa Finland • Tel358 10 7732 200 • www.vallox.com.
© VALLOX • We reserve the right to make changes without prior notification.
What the units include can vary depending on the sales area.
1.09.349E/11.10.2012/PDF
VALLOX 70 COMPACT
TROUBLESHOOTING
Outdoor air coming to the dwelling is cold.
REASON
• 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 the 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 (see page 7).
• Check the insulation of the attic ducts.
• Check the operation of the defrost thermostat and preheating resistor (see the section Preheating radiator on page
4). You may adjust the defrost thermostat by turning its spindle clockwise to +10
°
C or counter-clockwise to 0
°
C.
At 0
°
C freezing is likely; 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 +5
°
C.
• Check the operation of the radiator by comparing it with the curve (page 7). The curve shows the extent to which
extract air heats supply air without post-heating.
• Check that the filters and the heat recovery cell are clean.
• Check the initial adjustment.