Vallox TSK Multi 80 MC R Instructions For Use And Maintenance Manual Download

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• Air cools down in the attic ducts.
• The post-heating radiator, if there is one, does not work.
• The extract air filter or the cell is clogged.
• The initial adjustment of ventilation has not been done.
• The heat recovery cell is frozen, which is why extract air cannot heat outdoor air.

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, it may be caused by many reasons: 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 antifreeze thermostat.

1. Outdoor air coming to the dwelling is cold

• 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 antifreeze 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 antifreeze 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 heating is on.
The situation may pass by itself as soon as supply air temperature exceeds 10

C, but do not wait till it happens.

You can influence the operation of the antifreeze thermostat as follows:

• If freezing occurs in the cell, you can set the sensor closer to the cell, which makes the fan stop earlier (the cell has to

be thawed out before closing the cover).

• 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 likely; at 10

C no freezing occurs but extract air can be too warm when going