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Steam, a stopped outdoor fan and a temporary sound change can be normal during defrost. Learn when to request service.
Key decisionDecision: observe the full cycle. Brief steam can be normal; a unit trapped in ice needs inspection.
Why frost forms
Near freezing, moisture can freeze on the outdoor coil and reduce heat transfer. The heat pump temporarily reverses its cycle to melt that frost.
Normal signs
The outdoor fan may stop, the sound can change and steam may appear. The cycle should end and normal operation should resume.
When to call
Persistent buildup, a solid ice block, blocked drainage, unusual noise or prolonged loss of heat calls for inspection. Do not strike the ice or pour hot water on the unit.
Official sources
Updated :
Programs and criteria can change. Always verify the official source before making a decision.