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Error code reference

Frigidaire Air Conditioner Error Code FP

Low temperature prevention protection activated; unit enters pure electric heating mode.

Frigidaire codesFrigidaire air conditioner codes

Low temperature prevention protection activated; unit enters pure electric heating mode.

First step from the service manual

Check if indoor ambient temperature is lower than 40°F (5°C) continuously.

The complete diagnostic procedure includes additional test steps, resistance specifications, wiring diagram references, and component test points.

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What FP means on a Frigidaire air conditioner

The FP error code on a Frigidaire air conditioner indicates that the low temperature prevention protection system has been activated. This is a built-in protective function that triggers when the indoor ambient temperature drops below 40 degrees Fahrenheit (5 degrees Celsius) continuously. When this threshold is detected, the unit automatically exits any cooling or standard heat pump mode and transitions into pure electric heating mode to prevent damage to internal components, particularly the compressor and refrigerant circuit.

This protective response is necessary because heat pump systems rely on the refrigerant cycle to transfer heat, and when ambient temperatures fall too low, refrigerant pressures drop to levels that can cause the compressor to run dry or lose adequate lubrication. Ice formation on the indoor coil is also a risk at these temperatures. By switching to pure electric resistance heating, the unit bypasses the refrigerant cycle entirely and uses electric heating elements to maintain warmth without risking mechanical damage.

The primary diagnostic step is confirming whether the indoor ambient temperature is genuinely at or below 40 degrees Fahrenheit. If the space is unusually cold due to an open door, window, or a building heating failure, the FP code is functioning as designed and is not a fault in the traditional sense. However, if the indoor environment is clearly warmer than 40 degrees Fahrenheit, the issue may point to a faulty indoor ambient temperature sensor providing incorrect readings to the control board.

Source: manufacturer service documentation.

Common causes of FP

  1. 01

    Genuinely low indoor ambient temperature

    Wiring / connection

    If the indoor space has dropped below 40 degrees Fahrenheit due to cold weather, an open exterior door, or loss of building heat, the FP code is triggered by design. Check the room temperature with a thermometer to confirm.

  2. 02

    Faulty indoor ambient temperature sensor

    Part replacement

    A defective or out-of-calibration indoor ambient temperature sensor can report temperatures below 40 degrees Fahrenheit even when the actual room temperature is higher, causing a false FP activation. If the room is clearly warm but the code persists, the sensor should be tested and replaced.

  3. 03

    Poor unit placement or airflow restriction

    Wiring / connection

    If the air conditioner is installed near an exterior wall, uninsulated space, or has blocked airflow, the sensor near the intake may read abnormally cold temperatures even when the general room is warmer. Inspect the installation location and ensure intake vents are not obstructed.

  4. 04

    Control board malfunction

    Part replacement

    In some cases, a faulty main control board may misinterpret sensor signals or incorrectly engage the FP protection routine even with accurate sensor data. This is typically identified after ruling out sensor and environmental causes.

See the test procedure for each cause

Frequently asked questions about FP

What does FP mean on a Frigidaire air_conditioner?
The FP code on a Frigidaire air conditioner means the low temperature prevention protection has activated because the indoor ambient temperature has dropped to or below 40 degrees Fahrenheit continuously. When this happens, the unit automatically switches to pure electric heating mode to protect the refrigerant system and compressor from damage. It is a built-in safety function and does not always indicate a broken component.
How do I fix the FP error code on my Frigidaire air conditioner?
Start by checking whether the room temperature is actually below 40 degrees Fahrenheit using a separate thermometer. If it is, allow the space to warm up and the unit should exit FP mode on its own. If the room is clearly warmer than 40 degrees Fahrenheit and the code remains, the indoor ambient temperature sensor may be faulty and should be inspected or replaced.
Is the FP error code on a Frigidaire air conditioner dangerous?
The FP code itself is not a dangerous fault. It is a protective mode designed to prevent compressor and refrigerant system damage when temperatures are too low for normal heat pump operation. The unit continues to provide heat using electric resistance elements during this mode, so it does not leave the space without heating. However, if the code appears repeatedly in conditions that do not seem unusually cold, a sensor or board issue should be addressed promptly to avoid improper operation.
Will resetting my Frigidaire air conditioner clear the FP error code?
A manual reset by powering the unit off and back on may temporarily clear the FP display, but if the indoor temperature is still below 40 degrees Fahrenheit or a faulty sensor is present, the code will return. The underlying cause, whether environmental or component-related, needs to be addressed for the code to clear permanently. Simply resetting the unit without correcting the root cause is not a lasting solution.
How much does it cost to repair a Frigidaire air conditioner showing an FP code?
If the FP code is caused by genuinely cold indoor temperatures, there is no repair cost at all since it is normal protective behavior. If a faulty indoor ambient temperature sensor is responsible, sensor replacement parts typically range from around 15 to 60 dollars, with labor adding more if a technician is needed. A control board replacement, if required, generally costs between 100 and 300 dollars or more depending on the specific model.

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