How House Works

MrCool EC 07: outdoor fan speed out of control

By How House Works EditorialBased on MrCool manualsChecked against sources Updated

MrCool display

EC 07

“ODU Fan Speed Out of Control”

DIY 5th Gen, DIY Select, Easy Pro, Advantage 5th Gen, DIY 5th Gen Multi-Zone, DIY 5th Gen Cassette, DIY Hybrid Air Handler, Olympus Ducted · DIY 5th Gen owner's p. 39; Select owner's p. 41; Easy Pro owner's p. 41; Advantage 5th Gen owner's p. 46; DIY 5th Gen multi-zone owner's p. 48; DIY 5th Gen cassette owner's p. 45; Hybrid air handler owner's p. 56; Olympus ducted owner's p. 43
Owner checks, then technician

Also in the outdoor board tables (DIY 5th Gen Single-Zone Installation & Owner's Manual, p. 40). Service manual: the outdoor fan speed stays too low or too high for a certain time, the code shows and the system turns off (DIY 5th Gen Single-Zone Service Manual, p. 61).

What it means

EC 07 is about the outdoor unit’s fan. The DIY 5th Gen service manual says the code shows when the outdoor fan speed stays too low or too high for a certain time, and the system turns off DIY 5th Gen Single-Zone Service Manual, p. 61. The indoor fan has its own code, EH 03 DIY 5th Gen Single-Zone Installation & Owner’s Manual, p. 39. The outdoor board table lists EC 07 too, next to two other outdoor fan motor codes: EC 71, an overcurrent failure, and EC 72, a lack phase failure DIY 5th Gen Single-Zone Installation & Owner’s Manual, p. 40.

On 4th Gen units the operation lamp flashes 12 times with the timer lamp off DIY E Star 4th Gen Installation & Owner’s Manual, p. 41.

A stopped outdoor fan is not always a fault. The manuals describe these:

  • The outdoor fan does not run: in the DIY 5th Gen list of problems that are not a malfunction, the answer is that the fan speed is controlled during operation to optimize product operation DIY 5th Gen Single-Zone Installation & Owner’s Manual, p. 37.
  • The DIY 5th Gen dust removal function: after the unit is turned off, a 10 second delay occurs, then the outdoor fan runs in reverse for 70 seconds to blow off dust and debris DIY 5th Gen Single-Zone Installation & Owner’s Manual, p. 11.
  • On 4th Gen multi-zone units, the indoor and outdoor fans stop during defrosting DIY 4th Gen Multi-Zone Installation & Owner’s Manual, p. 14.

The code is the unit’s own judgment that the fan speed is abnormal. A fan you see stopped, or turning backward after shutdown, may be in one of these states.

Check these first

MrCool’s owner’s manuals give no steps for EC 07 itself. On the DIY 5th Gen, Select, Easy Pro, Advantage 5th Gen, cassette and Olympus manuals the procedure for any error code is:

  1. Wait about 10 minutes; the problem may resolve itself DIY 5th Gen Single-Zone Installation & Owner’s Manual, p. 38.
  2. If not, disconnect the power, connect it again and turn the unit on DIY 5th Gen Single-Zone Installation & Owner’s Manual, p. 38.
  3. If EC 07 comes back, disconnect the power and contact MrCool with your model number and a description of the problem DIY 5th Gen Single-Zone Installation & Owner’s Manual, pp. 37–38.

The hybrid air handler and 5th Gen multi-zone manuals print no wait-and-restart step; they say to contact a local dealer or MRCOOL customer service DIY Hybrid Air Handler Installation & Owner’s Manual, p. 54; DIY 5th Gen Multi-Zone Installation & Owner’s Manual, p. 46. The 4th Gen E Star and multi-zone manuals print the steps with “roughly 10 minutes” and add “DO NOT attempt these repairs yourself” DIY E Star 4th Gen Installation & Owner’s Manual, p. 41; DIY 4th Gen Multi-Zone Installation & Owner’s Manual, p. 49. The Advantage 4th Gen manual ends the steps with your nearest customer service center Advantage 4th Gen Owner’s and Installation Manual, p. 16. The 4th Gen cassette manual prints no steps; it says to contact a local dealer or the nearest customer service center DIY 4th Gen Cassette Installation & Owner’s Manual, p. 53.

Turn the unit off at once if it makes loud or abnormal sounds, or if water or objects fall into or out of the unit; the manual says not to fix these yourself DIY 5th Gen Single-Zone Installation & Owner’s Manual, p. 37. Its pre-season list asks you to make sure nothing blocks the air inlets and outlets DIY 5th Gen Single-Zone Installation & Owner’s Manual, p. 36. Leave anything beyond that to a professional: the manual says any maintenance and cleaning of the outdoor unit should be performed by an authorized dealer or a licensed service provider DIY 5th Gen Single-Zone Installation & Owner’s Manual, p. 36.

When to call a licensed technician

The parts the DIY 5th Gen service manual tells a technician to prepare for EC 07 are connection wires, the fan assembly, the fan motor and the outdoor main PCB DIY 5th Gen Single-Zone Service Manual, p. 61. The outdoor fan also comes up in the service manual’s checks for PC 03 and PC 04 DIY 5th Gen Single-Zone Service Manual, pp. 73–74.

This is technician work. The service manual warns that electricity remains in capacitors even when the power supply is off DIY 5th Gen Single-Zone Service Manual, p. 35, and the owner’s manual sends repairs to an authorized dealer or service provider DIY 5th Gen Single-Zone Installation & Owner’s Manual, p. 36.

Notes for different models

  • 4th Gen multi-zone: “The outdoor fan speed is operating outside of the normal range.” DIY 4th Gen Multi-Zone Installation & Owner’s Manual, p. 49; its outdoor unit table says “Outdoor fan speed has been out of control” DIY 4th Gen Multi-Zone Installation & Owner’s Manual, p. 50. The E Star, cassette and Advantage 4th Gen tables add “(for some models)”.
  • DIY E Star 3rd Gen: the outdoor fan code is F5, “Outdoor fan speed has been out of control”, with 6 operation LED flashes and the timer LED on DIY E Star 3rd Gen Installation & Owner’s Manual, p. 39.
  • The Advantage 4th Gen service manual covers the indoor and outdoor fan codes in one section headed “E3/EH 03 / F5/EC 07” Advantage 4th Gen Service Manual, Troubleshooting p. 23.

Related MrCool codes

  • EH 03 “IDU Fan Speed Out of Control”
  • EC 71 “Over Current Failure of ODU DC Fan Motor”
  • EC 72 “Lack Phase Failure of ODU DC Fan Motor”

See also

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

All MrCool codes

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

Sources

  1. MRCOOL. DIY 5th Gen Single-Zone Installation & Owner's Manual. Version Date August 5, 2026; file suffix -01; no document number printed. Cover title: DIY Series Single-Zone Mini-Split System, Installation & Owner's Manual. Accessed Oct 13, 2026.
  2. MRCOOL. DIY 5th Gen Single-Zone Service Manual. Version Date April 20, 2026; file suffix -01; no document number printed; same models as the owner's manual. Accessed Oct 13, 2026.
  3. MRCOOL. DIY Select Installation & Owner's Manual. Version Date August 5, 2026; no file suffix; no document number printed. Accessed Oct 13, 2026.
  4. MRCOOL. Easy Pro Installation & Owner's Manual. Version Date August 5, 2026; no file suffix; no document number printed. Cover title: MRCOOL DIY Easy Pro Mini-Split System. Accessed Oct 13, 2026.
  5. MRCOOL. Advantage 5th Gen Installation & Owner's Manual. Version Date September 19, 2025; file suffix -01; no document number printed. Accessed Oct 13, 2026.
  6. MRCOOL. DIY 5th Gen Multi-Zone Installation & Owner's Manual. Version Date January 8, 2026; file suffix -01; no document number printed. Its code table is titled “Error Display (Indoor Unit)” but lists outdoor unit codes.. Accessed Oct 13, 2026.
  7. MRCOOL. DIY 5th Gen Cassette Installation & Owner's Manual. Version Date December 02, 2025; file suffix -01; no document number printed. Cover title: DIY Series Outtasight One-Way Cassette. Accessed Oct 13, 2026.
  8. MRCOOL. DIY Hybrid Air Handler Installation & Owner's Manual. Version Date April 21, 2026; file suffix -01; no document number printed. Not linked from MrCool's documentation page on 2026-10-13; the file is on MrCool's own file host.. Accessed Oct 13, 2026.
  9. MRCOOL. Olympus Ducted Air Handler Installation & Owner's Manual. Version Date May 29, 2025; file suffix -01; no document number printed. Cover title: Olympus Series Mid-Static Ducted Air Handler. Accessed Oct 13, 2026.
  10. MRCOOL. DIY E Star 4th Gen Installation & Owner's Manual. Version Date 03-21-23; file suffix -01; no document number printed. Not listed on MrCool's documentation page on 2026-10-13; the file is on MrCool's own file host. It prints the same Version Date as the 3rd Gen E Star manual.. Accessed Oct 13, 2026.
  11. MRCOOL. DIY 4th Gen Multi-Zone Installation & Owner's Manual. Version Date 06-06-2023; file suffix -01; no document number printed. Not listed on MrCool's documentation page on 2026-10-13; the file is on MrCool's own file host.. Accessed Oct 13, 2026.
  12. MRCOOL. DIY 4th Gen Cassette Installation & Owner's Manual. Version Date 06-28-24; file suffix -01; no document number printed. Cover title: DIY Series Outtasight Ceiling Cassette Model DIYCASSETTE**HP-230C25. Accessed Oct 13, 2026.
  13. MRCOOL. Advantage 4th Gen Owner's and Installation Manual. Version Date 09-19-23; file suffix -01; no document number printed. Cover title: Advantage Series Owner's Manual + Installation Manual. It has no code table; the codes for this series come from the service manual.. Accessed Oct 13, 2026.
  14. MRCOOL. Advantage 4th Gen Service Manual. Version Date 7/06/22; file suffix -01; cover title Advantage Series Air Handler & Condenser Service Manual; pages are numbered within sections, cited as printed (Troubleshooting 5). It prints two lamp tables: one with letter codes (E1, P4, P6 and so on) and one with EH, EL, EC and PC codes. This table uses the second.. Accessed Oct 13, 2026.
  15. MRCOOL. DIY E Star 3rd Gen Installation & Owner's Manual. Version Date 03-21-23; file suffix -01; no document number printed. Not listed on MrCool's documentation page on 2026-10-13; the file is on MrCool's own file host. The code table's text layer is scrambled, so it was read from the page image.. Accessed Oct 13, 2026.