Goodman Error Code A3: Outdoor coil temperature sensor fault (Heat Pump)
Goodman error code A3 on a heat pump means: Outdoor coil temperature sensor fault. It is also called Goodman diagnostic code A3.
Homeowner? What Goodman code A3 means for you
Call a technician Your heat pump is reporting: Outdoor coil temperature sensor fault. The heat pump has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
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.
- Check both breakers and the outdoor disconnect box beside the outdoor unit; all should be ON.
- Look at the air filter. If it is grey and clogged, replace it; a blocked filter causes many shutdowns.
- In winter, keep snow and ice off and away from the outdoor unit. A short defrost cycle with steam is normal.
- 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) 657-2977Book a service call
Licensed technicians serving Vaughan, Toronto and the GTA.
What does Goodman error code A3 mean?
The outdoor coil temperature (OCT) sensor reads open, shorted, disconnected or out of range. This sensor drives defrost, so the heat pump will not run in heating while it is faulted.
Applies to: ComfortNet heat pumps ASZC/GSZC/DSZC (PCBHR104/105 outdoor control)
Common causes of Goodman code A3
- Sensor unplugged or loose at the outdoor control
- Open or shorted sensor or leads
- Sensor reading outside the valid range
Goodman models that use code A3
Show all 24 models
ASZC160241ASZC160361ASZC160421ASZC160481ASZC160601ASZC180241ASZC180361ASZC180481ASZC180601DSZC160241DSZC160361DSZC160481DSZC160601DSZC180361DSZC180481DSZC180601GSZC160241GSZC160361GSZC160481GSZC160601GSZC180241GSZC180361GSZC180481GSZC180601
Other Goodman Heat Pump codes
All Goodman Heat Pump error codes →
Goodman code A3: homeowner questions
What does Goodman code A3 mean?
Outdoor coil temperature sensor fault. The outdoor coil temperature (OCT) sensor reads open, shorted, disconnected or out of range. This sensor drives defrost, so the heat pump will not run in heating while it is faulted.
Is it safe to keep using my heat pump with code A3?
It depends on the cause. The heat pump has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.
Can I reset Goodman code A3 myself?
You can try one reset (power off for 30 seconds, then on). If Goodman code A3 comes back, the cause is still there and a licensed technician should check it.
Who can fix Goodman code A3 near me?
Aurora Star Tech Inc. repairs Goodman heat pumps in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.
Homeowner help: AC Running But Not Cooling: What to Check · Heat Pump Not Heating or Blowing Cold Air
Troubleshooting guides
- No heat - R-32 GLZS/ALZS heat pump Goodman · Heat Pump
- Outdoor coil iced / no defrost - R-32 GLZS/ALZS heat pump Goodman · Heat Pump
- Reversing valve not shifting - ComfortNet heat pumps Goodman · Heat Pump
Source: Goodman ComfortNet ASXC/GSXC/DSXC, ASZC/GSZC/DSZC, AVPTC/MBVC service manual, Unitary Diagnostic Codes PCBHR104 p.71-77 and PCBHR105 p.78-84; sensor check p.42-43. 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.