Short cycling: the outdoor unit is cycling on and off too quickly.
Homeowner part this code names: thermostat.
Search on AmazonOpens an Amazon search for that name. Check the size against your manual. As an Amazon Associate I earn from qualifying purchases.
Goodman 03 is short cycling: the outdoor unit is turning on and off too quickly. It is the next code after 01 and 02 on the same display, and it is not a pressure fault. Causes are an intermittent thermostat or thermostat wiring problem, a compressor relay or control board problem, loose low-voltage connections, and a main power or ground problem. Both steps are for a technician. Verify low voltage between R and Y. If it moves between 24 V and 0, check the thermostat and the wiring. If the system will not stay running, check the low-voltage connections and the compressor relay, replace the control if needed, and check main power and ground. Measuring R and Y means opening a cabinet that also holds line voltage, so it is not a homeowner check.
Likely causes
- Intermittent thermostat or thermostat wiring problem
- Compressor relay or control board problem
- Loose low-voltage connections
- Main power or ground problem
Safe checks for 03
- Technicianverify low voltage between R and Y; if it fluctuates between 24 V and 0, check the thermostat and thermostat wiring and repair or replace as needed
- Technicianif the system does not stay running, check low-voltage connections and the compressor relay; replace the control if needed, and check main power and ground
Capacitors can hold a charge after the power is off. Safety terms.
When to call a pro
Call a licensed HVAC technician to trace the thermostat wiring and control board.
Find a Goodman dealer (official locator, opens in a new tab) ↗Email me this fix
We save your email and this page. Nothing is emailed. We'll only use your email for this request.
Request a filter and maintenance reminder
We save your email, this page, and the interval you pick. Nothing is emailed. We'll only use your email for this request.
Parts & tools for this fix
Taken from this code's causes or steps. A search link opens Amazon results and does not confirm a fit. Check the model number in the manual.
Thermostat: guide
In this code: Intermittent thermostat or thermostat wiring problem
Multimeter for appliance and HVAC diagnosis: guide
In this code: Loose low-voltage connections
This one is for a technician to test or replace, so we only explain it and do not link to buy it.
As an Amazon Associate I earn from qualifying purchases.Affiliate disclosure