Goodman Furnace Leaking Water: Causes, Diagnosis, and Fixes

A leaking Goodman furnace can signal minor condensate problems or serious safety issues. This article explains common reasons a Goodman furnace leaking water, step-by-step diagnostics, practical DIY fixes, professional repair guidance, estimated costs, and prevention tips to protect home comfort and safety.

Common Cause	Symptoms	Quick Fix
Clogged Condensate Drain	Water pooling around furnace base, slow drainage	Clear drain line with wet/dry vacuum or vinegar
Faulty Condensate Pump	Pump runs but water remains, alarm on pump	Inspect pump, clean or replace pump
Cracked Heat Exchanger Or Primary Drain Leak	Rust, corrosion, persistent leaks, gas smell	Call certified technician immediately
Overflowing Secondary Pan	Water under furnace on subfloor, pan holes	Replace pan, add durable secondary pan
Improper Installation Or Wrong Slope	Intermittent leaks with heavy use	Re-level furnace, adjust piping

• Schedule Annual HVAC Maintenance With A Licensed Tech.
• Flush Condensate Lines With Vinegar Every 3–6 Months.
• Install A Condensate Float Switch That Shuts Off The Furnace On Overflow.
• Use A Secondary Pan With A Dedicated Drain And Alarm.
• Inspect The Furnace Area Regularly For Moisture Or Rust.
• Replace Aging Pumps And Hoses Before Failure.

Replacement Versus Repair: Making The Decision

Decide based on furnace age, repair cost, and efficiency. If repair costs exceed 50% of the furnace replacement price or the unit is older than 15 years with multiple failures, replacement usually provides better long-term value, improved efficiency, and warranty coverage.

Tools, Parts, And Materials Commonly Used

Item	Purpose
Wet/Dry Vacuum	Clears condensate line blockages
Pipe Brush Or Flexible Snake	Dislodges algae and debris
Condensate Pump Kit	Replaces failed lifting pumps
Corrosion-Resistant Secondary Pan	Captures overflow before floor damage
Vinegar Or Enzyme Cleaner	Sanitizes drain lines to prevent biological growth

Common FAQs About Goodman Furnace Leaks

Is It Normal For A Goodman Furnace To Leak Water?

Condensation is normal in high-efficiency Goodman furnaces, but visible water around the cabinet or on the floor is not. Proper drainage or a working pump should prevent floor leaks.

Can A Homeowner Safely Fix These Leaks?

Homeowners can handle drain clogs, trap cleaning, and pump cleaning if comfortable with basic safety practices. Electrical, gas, or suspected heat exchanger problems require a licensed technician.

How Long Can A Leaking Furnace Be Left Unrepaired?

Leaks should be addressed promptly. Even minor leaks can cause mold, wood rot, and electrical damage. If the cause is unknown, shut the unit off and contact a professional.

Practical Troubleshooting Checklist For Technicians

1. Verify Power Off And Gas Off Before Any Internal Work.
2. Document Water Source Location And Frequency.
3. Measure Condensate Line Diameter And Slope; Verify Trap Presence.
4. Test Condensate Pump Voltage And Float Switch Function.
5. Inspect Flue Venting For Proper Draft And Condensation Routing.
6. Perform A Combustion Analysis If Corrosion Or Heat Exchanger Concerns Are Present.

Key Takeaways For Homeowners

Prompt detection and maintenance prevent most Goodman furnace leaks. Regularly flushing condensate lines, testing condensate pumps, and inspecting secondary pans reduce risk. For persistent leaks, signs of corrosion, or any safety concern, engage a licensed HVAC technician to ensure safe, effective repair.