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3.3.3
Checking the fans
Even if the required maintenance, such as change of filters is carried out, dust and grease may slowly build up inside
the fans. This will reduce the efficiency.
The fans are easily taken out from the unit by loosening the 2 bolts (pos 1) on the rail (pos 2) and disconnecting the fast
couplings to the electric wires. Depending on the accessories installed, remove the tubing next to the fast couplings for
the extract air fan or both the extract air fan and supply air fan.
Clean the fans with a cloth or a soft brush with a recommended interval of once per year. Do not use water. White spirit
can be used to remove obstinate settlements. Allow drying properly before remounting.
3.3.4
Checking the hot water heating battery
After long periods of operation (usually several years) dust may have deposited on the surface of the battery. This may
reduce batteries capacity. The battery can be cleaned with a pressure washer with misting jets, or with compressed air.
Cleaning should be carried out carefully so as not to damage the batteries aluminium fins. Once a year the battery
water circuit needs to be vented to maintain the batteries capacity.
3.3.5
Checking the electrical heating battery
After long period of time dust and pollutants can build up on the heating rods. This can cause unpleasant odors and in
the worst case fire. Clean with compressed air, vacuum or brush. The automatic safety function needs to be tested and
verified.
3.3.6
Cleaning the extract louvres and inlet diffusers
The system supplies treated outdoor air to the building and extracts the used indoor air via the duct system and diffus-
ers/louvres. Diffusers and louvres are mounted in ceilings/walls in bedroom, living room, wet rooms, WC etc. Remove
diffusers and louvres and wash in hot soapy water if required. Diffusers/ louvres must be put back with their original
settings and positions in order not to unbalance the system.
The cleaning of these parts is done when necessary.
3.3.7
Checking the outdoor air intake
Leaves and pollution could plug up the air intake grille and reduce the unit’s capacity. Check the air intake grille at least
twice a year and clean if necessary.
3.3.8
Checking the duct system
Dust and grease settlements may build up in the duct system even if filters are changed regularly. This will reduce the
efficiency of the installation. The ducts should therefore be cleaned/changed when necessary. Steel ducts can be
154394 | A001
