Change the filter and run the fan-only setting for an hour to thaw it before calling anyone. If it freezes again within a day it is airflow or refrigerant, and that needs gauges. If a new filter fixes it, you saved a call.

This is most common in homes built roughly 1940 to 1980. Post-war and mid-century — copper supply, aging cast iron stacks, 60 to 100 amp panels, first-generation central air.

You can handle this one yourself. No call needed.

Related

• Ductwork threaded through a house built for floor grates
• One central return for the whole house
• Water heater vents into the chimney and the furnace no longer does
• Silver-wrapped tape on old duct joints
• Additions still on window units
• Uninsulated walls and an oversized condenser
• Furnace runs but the house never warms evenly
• Electrical panel cannot support a modern condenser

Back to Hvac.

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Written by Jaylan Jones. I Like To Fix earns a referral fee when a call connects to a contractor. See our business-model disclosure.