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HVAC - Preventative Maintenance

In this training module we take a look at the different aspects of preventative maintenance of an HVAC system, with emphasis on heat pumps. In particular, it outlines what tasks are to be performed by an HVAC contractor and what tasks are to be performed by the resident. It details procedures for inspection and corrective processes needed to keep an HVAC unit operating optimally and how often these tasks should be performed. Key terms are defined and explained in relation of preventative maintenance of HVAC units as well. 



  1. Remember

    • What is preventative maintenance, and who is responsible for this type of maintenance?
    • Understand key terms relevant for preventative maintenance of HVAC systems.
    • Understand the type of problems a technician may encounter when assessing HVAC system maintenance.
  2. Understand

    • Understand the general steps for HVAC contractors carrying out maintenance inspections for HVAC Systems.
    • Understand the general steps for HVAC contractors carrying out cleaning restoration for HVAC systems.
    • Understand how a homeowner can perform preventative maintenance on a ductless air source heat pump.
  3. Apply

    • Understand the inspection and maintenance tasks for different heat pump HVAC systems and their components.
    • Understand how to perform standardized cleaning on HVAC systems and ductwork.

Teaching Materials


Filters are an important component of ducted heating and cooling systems. When installed on the return side of the HVAC air handler, filters protect the HVAC motor and improve indoor air quality. They are installed in fresh air intakes to clean outside air that is brought into the home. 


Filters with higher MERV (Minimum Efficiency Reporting Value) ratings (MERV 6 and above) can trap pollutants like pollen, dust mites, and mold spores. However, a dirty or clogged filter can dramatically reduce air flow, increasing furnace run time, wear on the motor and energy consumption. Filters should be replaced or cleaned frequently and located in a place that is easily accessible for the homeowner.


If the furnace air handler is in an accessible location such as a utility room, it can be installed in the air handler at the return plenum. If the furnace is in the attic, the attic should be equipped with a staircase or pulldown stairs and a permanently installed walkway. The air handler box should be equipped with a filter media box with a gasketed removable access panel cover.

If the furnace air handler is located in an inaccessible location such as a crawlspace or attic without a staircase, a furnace filter should be located in each return grille.

If a fresh air intake is ducted to the air handler, a filter should be installed at the intake in an easily accessible location.