What do the error codes displayed by my camping air conditioner P502 (MD 37735) mean?

Tobo · ‎03.07.2025

Question

Answer

Problem	Possible cause	Solution
FL (water tank full)	Water tank of the outdoor unit full.	Empty the water tank.
	Check if the drainage pump is functioning correctly.	If the drainage pump is defective, contact MEDION-Service
	Check if the drain hose is pinched or kinked.	Lay the drain hose without bends.
EO (Communication error between the main control board and the UI board)	Circuit board error.	Contact MEDION-Service, possibly board replacement necessary.
E1 (Room temperature sensor failure)	Sensor terminals not properly plugged in.	Contact MEDION-Service, possibly sensor replacement necessary.
E2 (System temperature sensor failure)	Sensor terminals not properly plugged in.	Contact MEDION-Service, possibly sensor replacement necessary.
EF (Indoor unit feedback error)	Indoor unit motor defect.	Contact MEDION-Service, possibly motor / board replacement necessary.
EA (Four-way valve error)	Check if the four-way valve plug is correctly inserted.	Contact MEDION-Service, possibly four-way valve replacement necessary.
EC (Compressor overheating protection activated)	Room temperature too high.	Room temperature exceeds 40°C.
EC (Compressor overheating protection activated)	Refrigerant circuit damaged.	Do not operate the device in case of a leak. Contact MEDION-Service.
E4 (Ice formation)	Cooling or dehumidifying the device at low temperatures.	The E4 code displayed during cooling at low temperatures is normal and can be automatically reset.
E4 (Ice formation)	Check if the cold air outlet is blocked.	Ensure even air flow.