Pioneer · Air Conditioner error code

F1Outdoor ambient sensor (T4) fault

Cross-checked High-voltage / caution

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Related diagnostic guides

Guide · Air Conditioner

Heat pump outdoor coil iced over (not defrosting)

Light frost that clears every hour or so is normal. A solid block of ice means defrost isn't starting or finishing. Check outdoor fan, defrost sensor and board with a forced defrost before suspecting refrigerant.

6 steps ~60 minadvanced

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Pioneer air conditioner error F1: Outdoor ambient sensor (T4) fault · OnCall Tech