An HLK service contract allows a customer to use an individual or company to continue the maintenance and repair of their HLK system. This is usually a monthly retainer fee paid to a technician or company that has been commissioned to routinely test the system to ensure it is still working properly. An HLK system is an air-conditioned heating and cooling system for residential and commercial real estate. The system is designed to install filtered outdoor air in every room, while providing temperature adjustment. For this reason, it is recommended to modify the filters according to the use. An HLK technician is responsible for the installation, cleaning (filter change), repair and testing of an air conditioning system for a residential or commercial property….