Carrier 48FC Series - User Manual

Questions and Answers

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Jacob BondSep 23, 2025
What does Alert A110 mean on my Carrier 48FC Air Conditioner?
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  Edward WrightSep 23, 2025
  Alert A110 on your Carrier Air Conditioner indicates that the SPT sensor is out of range. This is usually due to a faulty thermistor or an incorrect thermistor caused by improper ohm reading. When this alert is active, cooling and heating will not operate.
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Jennifer PetersAug 23, 2025
What does Fault F010 mean on my Carrier Air Conditioner?
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  Kimberly ReedAug 23, 2025
  Fault F010 on your Carrier Air Conditioner indicates a low voltage issue, possibly due to a brownout, low supply voltage, or a missing phase in the supply power. The control system will shut down the unit, but it should automatically clear once the supply voltage rises above 19 volts AC.
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Kristin KirkAug 25, 2025
What does Fault F011 mean on my Carrier 48FC Air Conditioner?
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  Brandon HartmanAug 25, 2025
  Fault F011 indicates that the MBB reference voltage is out of range, usually due to an MBB failure or the supply voltage being out of range. The control system will shut down the unit. This fault should automatically clear when the DC reference voltage returns to its normal range.
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Jeffrey LambertAug 27, 2025
What does Alert A012 mean on my Carrier 48FC?
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  Marie MooreAug 27, 2025
  Alert A012 on your Carrier Air Conditioner signals an MBB zero crossing issue, often caused by an MBB failure or the supply voltage frequency being too high or too low. The alert should automatically clear once the supply voltage returns to the normal range.
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Ryan PearsonAug 27, 2025
What does Fault F013 mean on my Carrier Air Conditioner?
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  Brian RobinsonAug 28, 2025
  Fault F013 on your Carrier Air Conditioner indicates that MBB Fuse 2 is open, typically due to a wiring error in a switch input or the switch pulling too much current. The control will shut down the unit, but the fault should automatically clear when the fuse temperature returns to normal.
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Christopher CarrSep 18, 2025
What does Alert A107 mean on my Carrier 48FC Air Conditioner?
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  Javier BrownSep 18, 2025
  Alert A107 on your Carrier Air Conditioner indicates that the RAT sensor is out of range. This is usually due to a faulty thermistor, a shorted or open thermistor caused by a wiring error, or a loose connection. When this alert is active, no differential dry bulb crossover control can occur.
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garyfranklinSep 15, 2025
What does Alert A105 mean on my Carrier 48FC?
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  Melanie GrahamSep 15, 2025
  Alert A105 on your Carrier Air Conditioner indicates an open OAT sensor, generally caused by a faulty thermistor or an open thermistor due to a wiring error, or a loose connection. When this alert appears, the economizer will not operate for cooling.
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Christopher HernandezSep 16, 2025
What does Alert A106 mean on my Carrier Air Conditioner?
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  brandon75Sep 17, 2025
  Alert A106 on your Carrier Air Conditioner indicates a shorted OAT sensor, which is typically caused by a faulty thermistor or a shorted thermistor due to a wiring error, or a loose connection. If this alert is active, the economizer will not operate to provide cooling.
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Kathryn ReedSep 6, 2025
What does Fault F020 mean on my Carrier Air Conditioner?
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  sherricantuSep 6, 2025
  Fault F020 on your Carrier Air Conditioner indicates a software error, meaning the software on the MBB is not responding. Recovery is automatic if the software can reset the board. If not, try cycling the power to the control before considering board replacement.
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Joshua ClarkSep 4, 2025
What does Fault F018 mean on my Carrier 48FC Air Conditioner?
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  lcannonSep 4, 2025
  Fault F018 on your Carrier Air Conditioner indicates an MBB EEPROM failure, meaning the serial EEPROM chip on the MBB, which stores the unit’s configuration, is not responding. Recovery is automatic, but you might need to replace the MBB board. Before replacing the board, try cycling the power to the control.