Is It an Airflow Problem or an HVAC Problem?

01

Start with where the airflow changed

Weak air at every register points to a different check than one weak room or one floor. Note whether the system is heating or cooling normally, whether the problem follows one zone, and whether it started after filter work, construction, equipment service, or a thermostat change.

• One register or every register
• One room, one zone, or the whole property
• Heating, cooling, or both
• Constant or intermittent
• Recent work or a new sound

02

The equipment may not be moving or conditioning air correctly

A blower or equipment problem can reduce air across the system. Ice on cooling equipment, a blower that changes sound, or equipment that starts and stops are observations to report. They still do not name the failed component.

03

The filter, coil, or blower can restrict the shared air path

A loaded filter, dirty coil, or blower condition can affect many rooms because each sits in a shared path. ENERGY STAR's maintenance checklist includes filters, coils, blower components, controls, and condensate among the items that need attention during system checks.

04

Duct trouble usually follows the path to the room

A disconnected, crushed, blocked, poorly sealed, or undersized run can affect one branch or several rooms. Leakage, blockage, damage, and weak layout are different problems. Duct cleaning does not repair a disconnected run, and sealing does not remove a blockage.

05

The thermostat and zone controls decide when air is requested

A thermostat reading, zone panel, sensor, or damper relationship can make one area call while another does not. If airflow changes when a different zone starts, report that sequence. The control system and the duct path have to be checked together.

06

How is weak airflow diagnosed?

A useful check follows air from the return through the filter, equipment, blower, supply ducts, zone controls, and registers. Airflow measurement, visual inspection, and equipment readings can then separate an equipment fault from a restriction or duct problem without pretending the symptom already proved the answer.