When a Goodman heat pump with a diagnostic display stops on a fault, the control board shows a two-character code instead of its normal status. This guide lists the Goodman heat pump error codes, what each one means, what usually causes it, which ones you can check yourself and what the fix tends to cost.
The definitions come from Goodman’s own documents: the installation and service reference for its ComfortBridge heat pumps and condensing units (IOG-4009O, June 2023) and the service instructions for its ComfortNet heat pumps and air handlers (RS6200007). Both are written for technicians, so this guide puts them in plain English.
Does your Goodman show codes at all?
Not every Goodman heat pump has a code display. The codes in this guide come from the control board on Goodman’s communicating two-stage models: the GSZC7 and the earlier GSZC16, GSZC18 and DSZC series (the ComfortBridge and ComfortNet ranges). On those units, three small 7-segment digits on the control board inside the outdoor unit show the code.
If your outdoor unit has no display, it uses a simpler defrost control and the table below doesn’t apply. In that case the symptom is the clue: no heat, cold air, constant icing or a unit that won’t start. Our guides to a heat pump blowing cold air and a frozen heat pump cover those.
The display sits behind the outdoor unit’s service panel, next to live high-voltage wiring. Reading it is a job for your technician. What you can do is tell them what the system was doing when it stopped, and what the indoor unit or thermostat shows.
Codes that aren’t faults
On Goodman’s communicating air handlers, the indoor display also shows status codes during normal operation:
- dF means the system is defrosting. The outdoor coil is being warmed to melt frost, and Goodman ends a defrost when the coil reaches about 75°F or after 10 minutes, whichever comes first.
- H1 and H2 mean the electric backup heat is running on low or high stage. On non-communicating setups, H1 can also appear during defrost.
- h1 and h2 mean emergency heat, low or high.
- FC, FH and F mean the fan is running for cooling, for heating, or on its own.
Goodman outdoor unit error codes: full list
| Code | What it means | Usual causes |
|---|---|---|
| 01 | Low side fault (low-pressure trip) | Low refrigerant charge, a restriction in the liquid line, the indoor blower not running, or the thermostat set extremely low |
| L1 | Low-pressure lockout: three 01 trips | Same as 01. The unit stays off until power is cycled |
| 02 | High side fault (high-pressure trip) | Dirty or blocked outdoor coil, outdoor fan not running, a fan wiring fault or a failed fan capacitor |
| L2 | High-pressure lockout: three 02 trips | Same as 02. The unit stays off until power is cycled |
| 03 | Short cycling | The thermostat calling on and off intermittently, or a faulty compressor relay. The board enforces a 3-minute minimum run time |
| 04 | Locked rotor | Seized compressor bearings, a failed run capacitor or its wiring, or low line voltage |
| 05 | Open circuit | Power disconnected, a tripped breaker or blown fuse, a failed compressor protector or a compressor wiring fault |
| 06 | Open start circuit | Open start winding in the compressor, a capacitor fault or a wiring fault |
| 09 | Low control voltage (below 18 VAC) | Overloaded transformer, low line voltage or a fuse problem |
| P0 | Compressor protector open | No current through the compressor windings: an open run winding, a wiring fault or a capacitor fault |
| H8 | High line voltage (above 255 VAC) | The power supply to the house or unit is too high. Clears once voltage drops back below 255 VAC |
| L8 | Low or no line voltage (below 185 VAC) | Tripped breaker, blown fuse or low supply voltage |
| A2 | Outdoor air temperature sensor fault | Sensor shorted, open, unplugged or reading out of range. The heat pump won’t heat |
| A3 | Outdoor coil temperature sensor fault | Same as A2, for the coil sensor. The unit won’t run |
| E5 | Control fuse open | A short in the low-voltage (thermostat) wiring blew the board’s 3-amp fuse |
| EE | Control board fault | Compressor relay contacts welded shut. The board needs replacing |
| b0 | Indoor blower not running when it should be | Blower motor fault, indoor wiring, or lost communication between the indoor and outdoor units |
| b9 | Airflow lower than the system asked for | Clogged filter, restrictive or undersized ductwork, an indoor blower fault, or indoor and outdoor units that don’t match |
| d0 | System data not yet on the network | The communicating system hasn’t shared its setup data. Clears once the data loads |
| d1 | Invalid data on the network | Wrong or invalid setup data for the equipment |
| d2 | System mismatch | The outdoor unit needs more airflow than the indoor unit can supply, or the shared data is incompatible |
| d3 | Configuration mismatch | Setup data doesn’t match the installed hardware |
| d4 | Invalid memory card data | The control rejected the data on the installer’s memory card |
The d-codes almost always show up right after installation or a part replacement. They are a setup problem for the installer, not a failure of the equipment.
Goodman indoor unit (air handler) codes
Goodman’s communicating air handlers have their own display. When one of these codes appears, a communicating thermostat usually shows “Check Air Handler” or a call-for-service icon.
| Code | What it means | Usual causes |
|---|---|---|
| EF | Auxiliary switch open | High water level in the coil’s drain pan, usually a clogged condensate drain |
| Ec | Heat kit mismatch | The electric heat kit settings don’t match the system’s setup data |
| E5 | Fuse open | A short in the low-voltage wiring |
| EE | Internal fault or no power | Power off, a tripped breaker or blown fuse, or a loose 24-volt connection |
| b0 | Blower motor not running | Loose motor wiring or a failed motor |
| b1 | Blower motor not communicating | Loose control wiring, a failed motor or a failed control |
| b2 | Motor size mismatch | Wrong motor or wrong setup data |
| b3 | Motor at its power, temperature or speed limit | Blocked filter, restrictive ductwork or high ambient temperature |
| b4 | Motor current trip | Abnormal load or a sudden airflow blockage |
| b5 | Blower rotor locked | Something jammed in the blower housing, or seized bearings |
| b6 | Motor voltage or temperature fault | Incorrect line voltage or high ambient temperature |
| b7 | Motor didn’t receive its settings | A control error or repeated failed motor starts |
| b9 | Low indoor airflow | Blocked filter or restrictive ductwork |
| d0, d1, d4 | Setup data missing or invalid | Same meaning as on the outdoor unit |
A fault and a lockout aren’t the same
The most useful thing to understand about Goodman’s codes is the difference between a fault and a lockout.
A pressure fault (01 or 02) means a safety switch opened once. The board stops the compressor, waits and tries again. If the next cycles run normally, the code clears on its own: after three normal cycles for 01 and four for 02. That’s why the display can be blank by the time a technician arrives.
A lockout (L1 or L2) means the same switch opened three times. The board now stays off until someone cycles the 24-volt power, usually by turning the system off at the thermostat or switching the breaker off and on. Goodman treats a locked rotor (04) the same way.
Carrier works on similar logic with its fault code 84, a four-hour high-pressure lockout.
How to see past faults
The board keeps the six most recent faults, newest first. With the system idle, a technician presses the RECALL button for 2 to 5 seconds to scroll through them. Holding it longer than 5 seconds clears the history, which Goodman recommends after a repair.
Ask for that history to be read before any part is replaced, and to be cleared after the repair. A pattern, such as 02 every afternoon in summer or 01 every cold morning, says more than a single code.
What you can safely check yourself
- The air filter. Goodman lists a clogged filter as a cause of b9 and b3, and poor indoor airflow can also contribute to 01. Replace it if you can’t see light through it.
- Registers and returns. Make sure supply vents are open and nothing blocks the return grille.
- The outdoor unit. Clear leaves, snow, ice and anything stacked against it. A blocked outdoor coil is one of the causes Goodman lists for 02 and L2. With the power off, you can rinse the coil gently with a garden hose, never a pressure washer.
- Breakers. A tripped breaker or pulled disconnect gives 05 or L8. Reset it once. If it trips again, stop and call a technician.
- The condensate drain. EF on the air handler usually means the drain is clogged and the pan is full.
- The thermostat. Check the mode, the setpoint and the batteries. Intermittent thermostat calls cause 03.
Leave pressure switches, capacitors, refrigerant and the control board to a licensed technician. Jumping a safety switch to get the unit running can destroy the compressor.
How to reset a Goodman heat pump
Turn the system off at the thermostat, switch off the outdoor unit’s breaker for a minute, then restore power and turn the system back on. That cycles the 24-volt control power, which is what Goodman’s manual says clears lockouts such as L1, L2 and 04.
Reset once. If the same code comes back, the cause is still there. Repeated resets against a high-pressure or locked-rotor fault strain the compressor, the most expensive part in the system.
What Goodman repairs usually cost
| Repair | Likely codes | Typical cost |
|---|---|---|
| New filter, clearing the outdoor unit | b9, b3, 02 | $0 if you do it |
| Diagnostic visit | Any | $75–$250 |
| Run capacitor | 02, 04, 06, P0 | $100–$400 |
| Temperature sensor or defrost control | A2, A3, defrost problems | Less for a sensor; $200–$500 for a defrost board |
| Control board | EE, E5 (if the fuse keeps blowing) | $150–$700 |
| Outdoor fan or indoor blower motor | 02, L2, b0, b5 | $200–$1,000 (up to $1,500 for a variable-speed blower) |
| Reversing valve | Heating or cooling problems, no code | $350–$1,200 |
| Refrigerant leak repair | 01, L1 | $200–$1,500, plus the refrigerant |
| Compressor | 04, 06, P0 (once wiring and capacitor are ruled out) | $800–$4,000 |
Ranges come from PickHVAC (May 2026), Fixr (January 2026) and HVAC.com. If the part is under warranty, you mostly pay for labor. To compare the price of a whole new system instead, see our heat pump installation cost by state.
Is it covered by the warranty?
Goodman’s May 2025 warranty chart lists a 10-year parts limited warranty and a 10-year unit replacement limited warranty on models including the GSZC7 and GSZV9, but only if the system is registered online within 60 days of installation. Registration isn’t required in California, Florida or Québec. Check your registration before you pay for a part, and ask the technician to write the code and the fault history on the invoice.
Frequently asked questions
Where is the error code on a Goodman heat pump?
On ComfortBridge and ComfortNet models, it shows on a small three-digit display on the control board inside the outdoor unit’s service panel. Communicating air handlers have their own display, and a communicating thermostat may show “Check Air Handler” or a service icon.
What does L2 mean on a Goodman heat pump?
L2 is a high-pressure lockout: the high-pressure switch opened three times. Goodman lists a blocked outdoor coil, an outdoor fan that isn’t running, fan wiring or a failed fan capacitor as the usual causes. It stays locked out until the control power is cycled.
What does b9 mean on a Goodman?
The system is getting less airflow than it asked for. Start with the filter and make sure the vents and return grille aren’t blocked. If it continues, the blower or the ductwork needs checking.
Is dF an error?
No. dF on a Goodman communicating air handler means the heat pump is defrosting. A Goodman defrost ends when the outdoor coil warms to about 75°F or after 10 minutes at most.
How do I clear a Goodman error code?
Pressure faults such as 01 and 02 clear on their own after a few normal cycles. Lockouts such as L1, L2 and 04 clear when you cycle power at the thermostat or breaker. The board still keeps the last six faults in its history.
Sources
- Goodman, ComfortBridge heat pump installation and service reference, IOG-4009O (June 2023)
- Goodman, ComfortNet condensing units, heat pumps and air handlers service instructions, RS6200007r14 (December 2017)
- Goodman, residential warranty chart, PM-WARRCHRT-G (May 2025)
- PickHVAC, Heat Pump Repair and Parts Replacement Cost (May 2026)
- Fixr, How Much Does Heat Pump Repair Cost? (January 2026)
- HVAC.com, A Guide to Heat Pump Repair Costs