Goodman Error Code 09: Low 24 V control voltage (Heat Pump)
Goodman error code 09 on a heat pump means: Low 24 V control voltage. It is also called Goodman diagnostic code 09.
Homeowner? What Goodman code 09 means for you
Check, then call Your heat pump is reporting: Low 24 V control voltage. This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.
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 09 mean?
The control sees its 24 V supply below 18 VAC. The unit may still seem to run. Clears when the control voltage goes back above 21 VAC.
Applies to: Communicating 2-stage condensers and heat pumps with the PCBHR104 or PCBHR105 outdoor control (7-segment display): ASXC16/18, GSXC16/18, DSXC16/18, ASZC16/18, GSZC16/18, DSZC16/18
Common causes of Goodman code 09
- Overloaded transformer
- Low line voltage
- Fuse or wiring problem in the 24 V circuit
Goodman models that use code 09
Show all 24 models
ASZC160241ASZC160361ASZC160421ASZC160481ASZC160601ASZC180241ASZC180361ASZC180481ASZC180601DSZC160241DSZC160361DSZC160481DSZC160601DSZC180361DSZC180481DSZC180601GSZC160241GSZC160361GSZC160481GSZC160601GSZC180241GSZC180361GSZC180481GSZC180601
Other Goodman Heat Pump codes
All Goodman Heat Pump error codes →
Goodman code 09: homeowner questions
What does Goodman code 09 mean?
Low 24 V control voltage. The control sees its 24 V supply below 18 VAC. The unit may still seem to run. Clears when the control voltage goes back above 21 VAC.
Is it safe to keep using my heat pump with code 09?
It depends on the cause. This is often caused by something simple. Try the safe checks below; if the code returns, book a service call before it turns into a no-heat or no-hot-water emergency.
Can I reset Goodman code 09 myself?
You can try one reset (power off for 30 seconds, then on). If Goodman code 09 comes back, the cause is still there and a licensed technician should check it.
Who can fix Goodman code 09 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. 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.