Water & airflow · COMPONENT REFERENCE

Evaporator coil and filter troubleshooting

Transfers indoor heat to refrigerant while the air path and filter maintain usable airflow.

Failure causes

Choose a cause for symptoms, checks that separate it from similar faults, repair direction and verification.

Dirty filter or plugged indoor coil →A restricted air path reduces heat transfer and may lower coil temperature enough to freeze moisture.Restricted distribution or air leakage →Duct restrictions or leakage prevent the useful air delivery needed for comfort and coil loading.

References and applicability

Original HVACSim explanations with manufacturer and instrument-maker references for further reading. These resources support the subject; their model-specific examples are not specifications for every system.

Copeland: Refrigeration basics: troubleshooting fundamentalsCompressor and refrigerant troubleshooting concepts, not a charging specification.
Carrier: HVAC installation and commissioning overviewSizing, airflow, charge and A2L installation considerations; obtain the exact unit manual.

Editorial review: 2026-09-29. Verify the current manual for the installed model.