AC freezing up in Herndon, VA

An AC freezing up in Herndon, VA — ice forming on the indoor coil or the refrigerant lines outside — almost always traces back to restricted airflow or low refrigerant, not a "broken" unit outright.

Why it's icing over

• Restricted airflow — a dirty filter, closed vents, or blocked return air grilles are the most common cause
• Low refrigerant from a slow leak, which drops the coil temperature below freezing
• Running the AC when it's unusually cool outside (below ~60°F)
• A dirty evaporator coil that can't transfer heat properly
• A failing blower motor not moving enough air across the coil

What NOT to do

Turn the system off and let it thaw completely before a technician arrives — running an iced-up AC continues to stress the compressor and can turn a simple fix into a much more expensive one. Don't try to chip or scrape the ice off; let it melt on its own with the system off.

Herndon's humid summers mean a system that's borderline low on airflow or refrigerant is more likely to ice over here than in a drier climate — if this happens more than once in a season, it's worth having the root cause diagnosed rather than just thawing it out again.

Herndon HVAC contractors who diagnose frozen AC units

How this works

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