FA refers to the water level sensor circuit in the Haier combo units listed in the reference table. Diagnosis requires checking the system, not assuming a broken pressure switch.
The Haier Appliances documentation assigns FA to level detection and recommends service. It does not describe any household cleaning that would fix that circuit.
What information helps with diagnosis
Note whether it appears at power-on, while filling, or when it tries to drain. Observe whether there is retained water, a rising water level, or an external leak. If the water keeps rising, shut off the supply and stop using it; that condition takes priority over clearing the alarm.
Also keep any earlier message. E4 or E8 should only be considered if they actually appeared, not to choose another explanation for a persistent FA.
Do not blow into pressure lines, disconnect the sensor, or measure circuits with the appliance open. An external inspection can document the condition, but it does not prove the internal circuit is in good working order.
Request an inspection with the model, code, and recorded phase; avoid asking for a specific part before confirming the cause of the FA.