Goodman Furnace Error Code 10: How to Fix It

Q: What does error code 10 mean on a Goodman furnace?

Error code 10 indicates a 24V transformer fault. The furnace's control board is not receiving proper 24-volt power, often due to a short circuit or a failed transformer.

Q: Can I still use my furnace with error code 10?

No, the furnace will not operate safely with this error. The control board will lock out the furnace to prevent damage. You must fix the issue before using it.

Q: How do I reset a Goodman furnace after error code 10?

After fixing the cause, turn off power to the furnace for 30 seconds, then turn it back on. The error code should clear. If not, the issue is not resolved.

Q: What causes a 24V transformer fault on a Goodman furnace?

Common causes include a shorted low-voltage wire (e.g., thermostat wire touching metal), a failed transformer, a bad control board, or a shorted component like a pressure switch or gas valve.

Q: How much does it cost to replace a Goodman furnace transformer?

The transformer part typically costs $20–$50. If you hire a technician, expect labor costs of $100–$200 for diagnosis and replacement.

Abstract

Error code 10 on a Goodman furnace indicates a 24V transformer fault. This means the furnace's control board is not receiving the proper 24-volt power from the transformer, often due to a short circuit or a failed transformer. Follow these steps to diagnose and fix the issue safely.