14ServicePreventive maintenanceIntroduction The unit must be serviced at regular intervals to maintain a good indoor climate in thehouse, avoid breakdown or inefficient operation and maximise durability. It is importantto note that the intervals between services may vary depending on the environment inwhich the unit is installed.Warning Disconnect all power to the unit before beginning work! Only trained and certified engineers are permitted to service the internal parts ofthe unit. Users may replace filters Ensure that all work is completed and that the polystyrene front cover and the frontcover have been replaced before power is reconnected.Parts The following parts must be checked and/or replaced as required: Filters Fans Drip tray and internal surfaces Drain and discharge pipe Heat exchanger ControlsThe unit must also be serviced if it suddenly shows signs of unstable operations, vi-brates, leaks, makes a noise or other faults occur as described in the section on trou-bleshooting.Service intervals The table provides an overview of service intervals for different parts:Service interval Task To be carried out by0.5 years Filter check. Change if required UserExternal cleaning User1 year Filter replacement UserExternal discharge Certified engineer2 years Heat exchanger Certified engineerFans Certified engineerDrip tray/internal discharge Certified engineerInternal air ducts Certified engineerFilters and externalcleaningIntervals can be adapted to the use of the house and the outdoor air particle and smogcontent. See the user guide for details. Filters must, however, be checked every sixmonths. Dantherm Air Handling always recommends replacing filters at least once ayear.Check or replace filters when the filter alarm flashes yellow on the control panel whilebeeping (once an hour). Always reset the filter timer after a filter replacement by press-ing the filter reset button next to the filter for 2 seconds.Clean the unit externally and around the filter openings with a damp cloth to maintaingood hygiene. Filter replacement is described in detail in the user guideContinued overleaf