Goodman Error Code 9H: Goodman Code 9H - Soft Lockout
How to Fix Goodman Code 9H
- Step 1: Check your thermostat to ensure it is set to 'heat' and the temperature is set higher than the current room temperature.
- Step 2: Ensure the furnace power switch (usually on the side of the unit) is in the 'on' position.
- Step 3: Check your gas supply. Make sure the gas valve near the furnace is open. Also, check other gas appliances to see if they are working. If other gas appliances aren't working, there may be a gas supply problem that requires attention from the gas company.
- Step 4: If the furnace continues to display the 9H error after these checks, contact a qualified HVAC technician for diagnosis and repair.
How to Reset Goodman Code 9H
- Turn off the furnace power switch, usually located on or near the unit.
- Turn off the circuit breaker for the furnace. Wait 30 seconds.
- Restore power at the breaker and flip the furnace switch back on.
- Set the thermostat to call for heat. If the error code returns after 2-3 ignition attempts, the fault requires repair.
Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.
What Does Goodman Error Code 9H Mean?
The 9H error code on your Goodman furnace indicates a 'soft lockout.' This happens when the furnace attempts to ignite, but fails to establish a stable flame within a set period. The furnace control board, acting as the 'brain' of the system, detects this failure and shuts down the gas supply as a safety measure. After a short waiting period, the control board will automatically attempt to restart the ignition sequence. Repeated soft lockouts suggest an underlying issue preventing successful ignition. While the furnace will try to restart itself, it's important to address the root cause to prevent further lockouts and potential damage to the system. Ignoring this issue could eventually lead to a complete shutdown of your heating system, especially during cold weather.
Common Causes
- Dirty flame sensor preventing proper flame detection
- Weak or failing igniter unable to light the gas
- Low gas pressure to the furnace
- Blocked or restricted flue causing improper combustion
- Faulty gas valve not opening fully or reliably
Diagnostic Steps
| If... | Check | Expected |
|---|---|---|
| Furnace is in lockout and flame sensor is suspected | Measure flame sensor microamps (uA) during operation | At least 2 uA DC. Low reading indicates a dirty or faulty sensor. |
| Igniter is suspected | Measure igniter resistance with a multimeter | Typically between 40-90 ohms. Infinite resistance indicates a broken igniter. |
| Gas pressure is suspected | Measure gas pressure at the gas valve test port with a manometer | Typically 3.5"-4.0" WC for natural gas. Refer to the furnace's rating plate for specific pressure requirements. |
| Flue blockage is suspected | Visually inspect the flue pipe for obstructions. Check for proper draft with a manometer | No visible obstructions. Negative pressure indicates proper draft. |
Applicable Goodman Models
Recall Notices
Issued: November 1, 2021
Affected models: Molded plastic evaporator coil drain pans in up-flow condensing gas furnaces
Drain pans can overheat, melt, and deform, posing a fire hazard. Recall expanded January 2024.
Replacement Parts
| Part | OEM Number | Est. Cost | Where to Buy |
|---|---|---|---|
| Flame Sensor | 0130F00007 | — | Find Part |
| Hot Surface Igniter | 0130K00004S | — | Find Part |
| Gas Valve | — | — | — |
Related Codes on Same Models
Other codes that affect the same Goodman model families as 9H.
| Code | Description | Severity |
|---|---|---|
| 1 | System Lockout | Warning |
| 2 | Pressure Switch Stuck Closed | Warning |
| 3 | Pressure Switch Stuck Open | Warning |
| 4 | Open High Limit Switch | Warning |
| 5 | Flame Sensed With Gas Valve Off | Warning |
| 6 | Open Rollout Switch | Warning |
| 7 | Low Flame Signal | Warning |
| 8 | Ignitor Error | Warning |
| CONTINUOUS | Reversed Polarity | Warning |
| STEADY-ON | Normal Operation | Info |