Goodman Error Code RDS test mode: System verification test (simulated leak) (Air Handler)

Updated October 15, 2026 · by Aurora Star Tech Inc.

Goodman error code RDS test mode on a air handler means: System verification test (simulated leak). It is also called Goodman diagnostic code RDS test mode.

Low severityAir HandlerGoodman/Amana R-32 AMST/AWSF/ACSF air handlers

Homeowner? What Goodman code RDS test mode means for you

Usually minor Your air handler is reporting: System verification test (simulated leak). This code is usually informational or minor. The safe checks below often clear it; call us if it keeps showing up.

Safe things you can check yourself

Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
Make sure the unit has power: its on/off switch (often looks like a light switch near the unit) is ON and the breaker in the electrical panel is not tripped.
Look at the air filter. If it is grey and clogged, replace it; a blocked filter causes many shutdowns.
Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.

Call (647) 657-2977 Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Goodman error code RDS test mode mean?

Lets the contractor simulate an R-32 leak alarm to prove the system reacts. The red LED then flashes fast, as in a real leak alarm. The test runs 5 minutes and then returns to normal operation for up to 5 minutes. No other action is needed.

Applies to: AMST/AWSF/ACSF R-32 air handlers

Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

Goodman models that use code RDS test mode

ACSF****13**AA AMST***U1300AA AWSF****13**AA AWST****13**AA

Other Goodman Air Handler codes

Code	Meaning
RDS 2 flashes	Control board internal fault (leak detection board)
RDS 3 flashes	R32 sensor communication fault
RDS 4 flashes	R32 sensor internal fault
RDS fast flash	R-32 leak alarm (or system verification test)
RDS slow flash	Normal operation - leak detection OK
RDS steady on	Delay mode after leak alarm or fault
Rx LED rapid flash	Green receive LED rapid flashing - normal network traffic

All Goodman Air Handler error codes →

Goodman code RDS test mode: homeowner questions

What does Goodman code RDS test mode mean?

System verification test (simulated leak). Lets the contractor simulate an R-32 leak alarm to prove the system reacts. The red LED then flashes fast, as in a real leak alarm. The test runs 5 minutes and then returns to normal operation for up to 5 minutes. No other action is needed.

Is it safe to keep using my air handler with code RDS test mode?

Usually yes. Code RDS test mode is normally minor, but if it keeps coming back have it checked.

Can I reset Goodman code RDS test mode myself?

You can try one reset (power off for 30 seconds, then on). If Goodman code RDS test mode comes back, the cause is still there and a licensed technician should check it.

Who can fix Goodman code RDS test mode near me?

Aurora Star Tech Inc. repairs Goodman air handlers in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Troubleshooting guides

Blower not running - R-32 AMST/AWSF EEM air handler Goodman · Air Handler
No electric heat - R-32 air handler heat kit Goodman · Air Handler
Outdoor unit not communicating - ComfortBridge AVPTC/MBVC Goodman · Air Handler
Restart indoor-outdoor communication (Lrn) Goodman · Air Handler
Run the R-32 leak alarm test (RDS test mode) Goodman · Air Handler
View and clear the 6 most recent faults (FCL / L6F) Goodman · Air Handler

Source: R-32 GLXS/GLZS and AMST/AWSF service RS6200301, RDS A2L PCB FAULT CODE table p.25 and Recommended Action table p.26. Written in our own words as a summary; always check the original manual.

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.