Diagnose Sudden Heat Loss in One Room

Cost Savings

Checklist Tasks

• Confirm the room’s supply vent is open and unobstructed to ensure airflow.
• Remove the vent cover and look for collapse, disconnection, or blockages in ductwork.
• Check for stuck or closed balancing dampers in the branch duct.
• Use an infrared thermometer to locate cold spots caused by drafts or insulation gaps.
• Inspect exterior walls and windows for new gaps, drafts, or weatherstripping failure.
• Test the room’s thermostat for accurate function and placement.
• Examine return air pathways for clear, unblocked circulation.
• Check attic or crawl space insulation above or below the affected room.
• Inspect ducts for pest activity or chewed insulation causing heat loss.
• Verify zone valves or dampers if using a multi-zone HVAC system.
• Check for water leaks or moisture affecting insulation or surfaces.
• Ensure the HVAC filter is clean and recently changed to support airflow.