Building facade with window and wall air conditioner units

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PTAC not heating (electric heat or heat pump)

PTACs heat with electric strip heat, a heat pump, or both. Heat pump models switch to strip heat in cold weather. Check settings, then the heater element and its limits, then the reversing valve.

Single source ~60 min moderateBrands: All

Before you start

Disconnect power before testing heaters and limits
Live current checks are a caution step: insulated probes, one hand
Inverter and capacitor-start units hold dangerous voltage after power-off; wait the time on the label and verify 0 V DC before touching boards or capacitors

Diagnostic steps

Unlock all 5 steps with expected values

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OnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work.

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