DIY HVAC Tools

Goodman mini split error code A9

Indoor electronic expansion valve (EEV) fault.

  • TypeFault
  • SystemRefrigerant circuit
  • Can I fix it?Technician job

What A9 means on a Goodman

The electronic expansion valve in the indoor unit (multi-split and some singles) did not respond correctly.

On this platform, A9 is a fault: something has failed or is disconnected and needs diagnosis.

Common causes

  • A loose EEV coil connector.
  • A failed EEV coil or a stuck valve body.
  • A failed board output.

How to fix it yourself

Do the reset and the visual checks, but the underlying repair needs a technician with a meter and the service manual.

  1. Reset the system: switch the breaker (or the outdoor disconnect) off, wait a full five minutes so the boards fully discharge, then switch it back on and restart from the remote.
  2. With power off, check the EEV coil plug is seated on the board.

Switch off power at the breaker before opening either unit. Capacitors in the outdoor unit hold a charge for several minutes after power is cut.

When to call a technician

Valve body replacement is a sealed-system job for a technician.

Which Goodman units show A9

This page applies to Goodman e-Series wall-mount (FTXNG indoor / RXNG outdoor) units. Goodman's own documentation lists A9 as "Indoor electronic expansion valve (EEV) fault", the same definition used across the Daikin it is built on. If your unit shows a code with a different shape (for example a four-character code, or a plain number), it is from a different table; use the lookup with your exact code.

Where Goodman shows this code

Most Daikin wall units do not show the code on the unit; the operation lamp blinks. To read the code, point the remote at the unit, hold CANCEL (or Timer Cancel) for about 5 seconds until 00 shows, then press CANCEL repeatedly. Each press shows a code; when the unit gives a long continuous beep instead of two short beeps, the code on the remote is the stored fault. Units with a wired controller show the code directly. A and C codes are indoor-unit faults, E, F, H, J, L and P codes are outdoor-unit faults and protections, and U codes are system-level problems such as communication, power supply and refrigerant shortage.

Other Goodman codes

Same part of the system as A9:

A5Freeze-up protection (cooling) or high-pressure control (heating)E3High pressure protection (high-pressure switch)E4Low pressure protectionEAFour-way (reversing) valve switching faultF6High pressure in cooling (refrigerant overcharge)U0Refrigerant shortage
00No fault stored (normal)A1Indoor unit control board (PCB) failureA3Drain water level abnormal (float switch)A6Indoor fan motor fault (locked or abnormal)C4Indoor heat exchanger (liquid pipe) temperature sensor fault (open or short circuit)C5Indoor heat exchanger (gas pipe) temperature sensor fault (open or short circuit)C7Front panel (open/close) drive faultC9Indoor room (suction air) temperature sensor fault (open or short circuit)

All Goodman error codes

A9 on other brands

The same characters do not always mean the same thing. Check the brand on your unit.

  • Daikin A9 Indoor electronic expansion valve (EEV) fault

Questions people ask

Can I reset a Goodman A9 code myself?

Yes. Turn the system off at the breaker for five minutes, then restart it. If A9 comes back, the fault is real and needs the checks above.

Is it safe to keep running a Goodman showing A9?

The unit will usually refuse to run, or run with reduced output, until the fault is cleared. Repeated resets do not fix anything and can mask a problem that is getting worse.

What will a technician check for A9?

Valve body replacement is a sealed-system job for a technician. Ask for the measurements, not just a parts quote.

Sources

  • Goodman e-Series product documentation (FTXNG / RXNG models)
  • Daikin residential (RA) service manuals (error code tables)

Updated September 2026. Codes and definitions vary by model year. If your manual disagrees with this page, your manual wins. Send a correction.