How House Works

Daikin EA: cooling-heating switching error

By How House Works EditorialBased on Daikin manualsChecked against sources Updated

Daikin remote controller display

EA

“COOLING-HEATING SWITCHING ERROR”

FTXM-WVJU9, FTXQ-ASBU9, FTX/FTXN-NMVJU, FTXS30/36 · FTXM-WVJU9 Operation Manual, p. 50; FTXQ-ASBU9 Operation Manual, p. 28; FTX/FTXN-NMVJU Operation Manual, p. 30; FTXS30/36 Operation Manual, p. 36
Technician

The FTXM-W/V service manual calls EA “Four way valve abnormality” (FTXM-W/V Service Manual SiUS042113EA, p. 96).

What it means

The owner’s tables call EA a cooling-heating switching error; the service manuals call the same code a four way valve abnormality FTXM-WVJU9 Operation Manual, p. 50; FTXM-W/V Service Manual SiUS042113EA, p. 96.

The check uses two indoor sensors, the room thermistor and the indoor heat exchanger thermistor. The FTXM-W/V service manual sets EA when, after 5 to 10 minutes of operation and for 1 to 10 minutes after that (depending on the model), the indoor heat exchanger reads more than 9°F (5°C) warmer than the room in cooling or dry mode, or more than 9°F (5°C) colder than the room in heating. If EA repeats, the system shuts down; it resets after about 60 minutes of continuous running without any other error FTXM-W/V Service Manual SiUS042113EA, p. 120. The FTXS-L manual gives the same limits; the FTX-W manual uses 10 minutes after 5 minutes of operation FTXS-L Service Manual SiUS091133, p. 119; FTX-W Service Manual SiUS042228E, p. 91. The FTK-B/FTX-B manual adds the outdoor thermistors to the check and prints the limit as “-5°C (23°F)” FTK-B/FTX-B Service Manual DAMA-SM-23-006, p. 89.

The owner’s manuals’ FAQ explains two related things. In heating, the unit stops with a flowing sound while the outdoor unit defrosts, for about 4 to 12 minutes. A blowing sound is heard when the refrigerant flow is switched over, for example when the flow direction changes at the start of defrost FTXM-WVJU9 Operation Manual, p. 45; FTXQ-ASBU9 Operation Manual, p. 23.

Check these first

The owner’s manuals have no step written for EA itself:

  1. Check that the OPERATION lamp blinks at about 0.5-second intervals and read the code, as described in the Daikin code guide FTXM-WVJU9 Operation Manual, p. 49; FTXQ-ASBU9 Operation Manual, p. 27.
  2. Turn off the power with the circuit breaker, then restart with the remote controller FTXM-WVJU9 Operation Manual, p. 46; FTXQ-ASBU9 Operation Manual, p. 24; FTX/FTXN-NMVJU Operation Manual, p. 27. If you stopped the unit yourself, the manual’s caution is to wait at least 5 minutes after stopping before turning off the power, or water may leak FTXM-WVJU9 Operation Manual, p. 4. After the breaker goes on, allow about 3 to 10 minutes before the unit runs FTXM-WVJU9 Operation Manual, p. 47.
  3. Watch the lamp. EA is one of the “Other error codes” in the FTXM-WVJU9 and FTXQ-ASBU9 charts: if the lamp stays lit after the unit has run for a while, keep using it; if it blinks again, turn off the circuit breaker and call your dealer FTXM-WVJU9 Operation Manual, pp. 49–50; FTXQ-ASBU9 Operation Manual, pp. 27–28.

FTXS30/36 owners have the manual’s general steps for a flashing lamp: clean the filters, remove obstacles at the indoor and outdoor units, turn the breaker off and on, and call the service shop if it still flashes FTXS30/36 Operation Manual, p. 34.

When to call a licensed technician

The FTXM-W/V service manual lists these causes for EA FTXM-W/V Service Manual SiUS042113EA, p. 120:

  • a disconnected four way valve coil, or a defective four way valve, coil or harness;
  • a defective outdoor unit PCB or a defective thermistor;
  • refrigerant shortage, water mixed in the refrigerant, or a defective stop valve.

The AXVJU manual adds foreign substance mixed in the refrigerant AXVJU Service Manual SM-5WM-Y-NA-B1, p. 45. EA sits in the OUTDOOR UNIT group of the owner’s tables FTXM-WVJU9 Operation Manual, p. 50, and several of the causes involve the refrigerant circuit. Refrigerant work is for a technician certified under EPA Section 608. Daikin’s service manual says: “Servicing shall be performed only as recommended by the manufacturer and licensed or certified in their jurisdiction.” FTXM-W/V Service Manual SiUS042113EA, p. 2.

Notes for different models

  • FTX/FTK-BXVJU and the remote manuals call EA “4 way valve error” FTX/FTK-BXVJU Operation Manual, p. 1, section 9; BRC52B Remote Controller Manual, p. 1-3; BRC51D61 Wired Remote Controller Manual, p. 11. The AXVJU service manual: “4 WAY VALVE ABNORMALITY” AXVJU Service Manual SM-5WM-Y-NA-B1, p. 34.
  • EA is in the owner’s tables of all four grouped-table series: FTXM-WVJU9, FTXQ-ASBU9, FTX/FTXN-NMVJU and FTXS30/36 FTXM-WVJU9 Operation Manual, p. 50; FTXQ-ASBU9 Operation Manual, p. 28; FTX/FTXN-NMVJU Operation Manual, p. 30; FTXS30/36 Operation Manual, p. 36.

Related Daikin codes

  • C4 “FAULTY HEAT EXCHANGER TEMPERATURE SENSOR”
  • C9 “FAULTY SUCTION AIR TEMPERATURE SENSOR”
  • U0 “REFRIGERANT SHORTAGE”

See also

Other ductless mini-splits: Fujitsu, Mitsubishi Electric, MrCool

All Daikin codes

Daikin is a trademark of its owner. How House Works is not affiliated with or endorsed by Daikin.

Sources

  1. Daikin Comfort Technologies North America (document library). FTXM-WVJU9 Operation Manual. 3P686871-1A, page stamp 2022/05/30; covers FTXM09/12/18/24WVJU9. Listed under ATMOSPHERA in Daikin's document library.. Accessed Oct 13, 2026.
  2. Daikin Comfort Technologies North America (document library). FTXQ-ASBU9 Operation Manual. 3P741457-13J, English; page stamp 2024/11/19; covers FTXQ09ASBU9 and FTXQ12ASBU9. Listed under OTERRA 115V. The library list shows only the French and Spanish files of this manual; the English file is served at this address.. Accessed Oct 13, 2026.
  3. Daikin Comfort Technologies North America (document library). FTX/FTXN-NMVJU Operation Manual. 3P379751-4C, page stamp 11/6/2015; covers FTX09/12/15/18/24NMVJU and FTXN09/12/18/24NMVJU. Not in Daikin's current library list; the file is still served from daikincomfort.com.. Accessed Oct 13, 2026.
  4. Daikin Comfort Technologies North America (document library). FTXS30/36 Operation Manual. 3P228444-4K, page stamp 3/28/2013; covers FTXS30HVJU, FTXS36HVJU, FTXS30LVJU and FTXS36LVJU. Not in Daikin's current library list; the file is still served from daikincomfort.com.. Accessed Oct 13, 2026.
  5. Daikin Comfort Technologies North America (document library). FTX/FTK-BXVJU Operation Manual. 3P601789-2 E (cover label); no printed date; covers FTX, FTXB and FTK09/12/18/24BXVJU; R410A. A poster with one page per language (English, Spanish, French) and no page numbers: citations give PDF page 1 and the poster section. The same file is also listed under ENTRA.. Accessed Oct 13, 2026.
  6. Daikin Comfort Technologies North America (document library). BRC52B Remote Controller Manual. OM-BRC52B-0617(2)-DAIKIN USA, Part No. R08019046595B; print stamp 10/30/2017; covers remote controllers BRC52B61/62/63/64/65. Does not name the indoor units. The library lists it under ENTRA.. Accessed Oct 13, 2026.
  7. Daikin Comfort Technologies North America (document library). BRC51D61 Wired Remote Controller Manual. R08019049297B; print stamp 7/12/2022. Does not name the indoor units. The library lists it under OTERRA (cooling only) and ENTRA.. Accessed Oct 13, 2026.
  8. Daikin Comfort Technologies North America (document library). FTXM-W/V Service Manual SiUS042113EA. SiUS042113EA, revision of 01/2023; covers FTXM09/12/18/24WVJU9 and FTXM-VVJU with RXM outdoor units. Accessed Oct 13, 2026.
  9. Daikin Comfort Technologies North America (document library). FTK-B/FTX-B Service Manual DAMA-SM-23-006. DAMA-SM-23-006, first edition 04/2023; covers FTK09/12/18/24BXVJU and FTX09/12/18/24BXVJU with RK/RX-BXVJU outdoor units. Accessed Oct 13, 2026.
  10. Daikin Comfort Technologies North America (document library). AXVJU Service Manual SM-5WM-Y-NA-B1. SM-5WM-Y-NA-B1; no printed date (PDF created 2021-09-29); covers FTKB/FTKN/FTXB/FTXN09/12/18/24AXVJU. Listed under ENTRA.. Accessed Oct 13, 2026.
  11. Daikin Comfort Technologies North America (document library). FTX-W Service Manual SiUS042228E. SiUS042228E, first edition 10/2022; covers FTX30/36WVJU9 with RK30/36WMVJU9 or RX30/36WMVJU9. Listed under POLARA.. Accessed Oct 13, 2026.
  12. Daikin Comfort Technologies North America (document library). FTXS-L Service Manual SiUS091133. SiUS091133; no printed date (PDF created 2013-01-11); covers FTXS09–36LVJU and FDXS09/12LVJU. Not in Daikin's current library list; the file is still served from daikincomfort.com.. Accessed Oct 13, 2026.