Daikin Error Code EA: Four Way Valve Abnormality (Cool/Heat Switching) (Meaning, Causes, Fixes)
What the code means
Daikin's service manuals call EA "Four Way Valve Abnormality." The four way valve (reversing valve) in the outdoor unit switches the refrigerant flow between cooling and heating. To check it, the control compares the room temperature thermistor with the indoor heat exchanger thermistor. In cooling or dry mode the coil should be colder than the room; in heating it should be warmer. If, after 10 minutes of running, the coil is more than 5 °C (9 °F) on the wrong side of room temperature for over a minute, the unit flags EA. If the error repeats (five times on the B series manual), the system shuts down. The code resets after about 60 minutes of normal running with no other error. Because the check relies on the indoor thermistors, a failed or misplaced coil thermistor can trigger EA even when the valve itself is fine. This page covers Daikin ductless wall-mount and similar residential mini splits; VRV systems use their own code lists.
Likely causes
- The four way valve coil is loose or has come off the valve, or its connector has come out of the outdoor board.
- A defective four way valve coil or harness (an open or out-of-range coil resistance).
- A four way valve that is stuck or clogged with debris and won't switch.
- A faulty or disconnected room or indoor heat exchanger thermistor giving a wrong temperature reading.
- A defective outdoor unit PCB that isn't sending the switching output to the valve coil.
- Low refrigerant charge, moisture or foreign matter in the refrigerant, or a stop valve that is closed or defective.
Safe DIY checks
The four way valve coil and outdoor board run on line voltage, and inverter boards can hold a charge after power is off. Turn the power off at the breaker before touching any connector, as Daikin's manual cautions. Refrigerant work and valve replacement require an EPA-certified technician.
- Check the remote is set to the mode you want (cool, dry or heat) and that the set temperature makes sense for that mode.
- Turn the system off, switch off the breaker for both units for a few minutes, then restore power and restart. Daikin's code clears after about an hour of normal running without another error.
- Make sure the indoor and outdoor coils have clear airflow: clean the indoor filters and clear leaves, snow or debris from around the outdoor unit.
- If the unit was just installed or moved, confirm with the installer that both stop valves at the outdoor unit were fully opened.
- If EA keeps coming back, note the code and your model numbers and call a licensed HVAC technician. The remaining checks involve live electrical parts and refrigerant.
🛠 When to call a pro
- Checking that the four way valve coil is seated on the valve and its harness is plugged into the outdoor board, as the first step in Daikin's flowchart.
- Measuring the valve coil resistance; Daikin's Entra wall-mount manual gives about 1,000 to 2,000 ohms for 9k/12k units and 560 ohms plus or minus 56 for 18k/24k units. Replace the coil if it is out of spec.
- Checking the outdoor board's four way valve switching output, and replacing the outdoor PCB if it doesn't switch.
- Testing the room and indoor coil thermistors against Daikin's resistance tables, reconnecting or replacing any that are disconnected or out of range.
- Checking the refrigerant circuit for low charge, moisture or a stuck stop valve, and replacing the four way valve if it is defective or clogged.
Parts that commonly fix it
Always match the part number to your exact model.
Daikin thermistor
Only if a technician finds the room or indoor coil thermistor out of range; match the indoor unit model number.
Search eBay →Digital multimeter
For checking the four way valve coil resistance and thermistor values with the power off.
Search eBay →Refrigerant leak detector
For a technician to confirm whether low refrigerant is behind the code.
Search eBay →Sources
Last reviewed 2026-10-24. Always confirm against the manual for your exact model number.