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    hvac troubleshooting

    Ice on lines/coil observed

    Common symptoms: ice on lines; frozen coil; frost on pipes; ice on ac

    Stop and call a pro if:

    • smoke
    • sparks
    • burning odor
    • water near electrical

    Step-by-step diagnostic flow

    1. Step 1

      Any burning smells, smoke, sparks, or water near electrical?

    2. Step 2

      Is indoor airflow present at vents?

    3. Step 3

      Visually check filter/vents for dust buildup or blockage.

    4. Step 4

      How much ice is visible without opening panels?

    Possible outcomes

    Stop and seek professional help immediately

    high confidence

    Safety hazard detected.

    Airflow restriction likely

    high confidence

    Visual blockage can cause freeze-up.

    Safe next steps
    • Photograph filter and vents
    • List rooms with closed/blocked vents
    What to document for a pro
    • Filter size/MERV

    Frozen evaporator coil likely

    medium confidence

    Significant ice observed.

    Safe next steps
    • Turn system off to allow thawing; do not open sealed panels
    • Capture photos and timeline
    What to document for a pro
    • Supply/return temps if available
    • Photos of ice

    Further professional diagnosis recommended

    low confidence

    Non-invasive checks inconclusive.

    Safe next steps
    • Record sounds, cycle timing, thermostat settings
    Diagnostic guidance only. If unsure, stop and call a licensed professional — gas, electrical, and refrigerant work is hazardous to untrained users.

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