General

Did the service provider obtain access to and clean the entire heating and cooling system, including ductwork and all components (drain pans, humidifiers, coils, and fans)?

Has the service provider adequately demonstrated that duct work and plenums are clean? (Plenum is a space in which supply or return air is mixed or moves; can be duct, joist space, attic and crawl spaces, or wall cavity.)

Heating

Is the heat exchanger surface visibly clean?

Cooling Components

Are both sides of the cooling coil visibly clean?

If you point a flashlight into the cooling coil, does light shine through the other side? It should if the coil is clean.

Are the coil fins straight and evenly spaced (as opposed to being bent over and smashed together)?

Is the coil drain pan completely clean and draining properly?

Blower

Are the blower blades clean and free of oil and debris?

Is the blower compartment free of visible dust or debris?

Plenums

Is the return air plenum free of visible dust or debris?

Do filters fit properly and are they the proper efficiency as recommended by HVAC system manufacturer?

Is the supply air plenum (directly downstream of the air handling unit) free of moisture stains and contaminants?

Metal Ducts

Are interior ductwork surfaces free of visible debris? (Select several sites at random in both the return and supply sides of the system.)

Fiber Glass

Is all fiber glass material in good condition (i.e., free of tears and abrasions; well adhered to underlying materials)?

Access Doors

Are newly installed access doors in sheet metal ducts attached with more than just duct tape (e.g., screws, rivets, mastic, etc.)?

With the system running, is air leakage through access doors orcovers very slight or non-existent?

Air Vents

Have all registers, grilles, and diffusers been firmly reattached to the walls, floors, and/or ceilings?

Are the registers, grilles, and diffusers visibly clean?

System Operation

Does the system function properly in both the heating and cooling modes after cleaning?