Navien Tankless Water Heater Error Code 009: How to Fix It
Medium 45-90 minutes Medium Severity
Verified June 2026
- Error Code
- 009
- Brand
- Navien
- Product Type
- water_heater
- Severity
- Medium
- DIY Difficulty
- Medium
- Estimated Fix Time
- 45-90 minutes
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Tools You'll Need
- Multimeter
- Manometer (gas pressure gauge)
- Screwdriver set
- Adjustable wrench
- Soapy water (for leak testing)
How to Fix Error Code 009
-
Safety First: Turn Off Power and Gas
Always turn off power and gas before working on the appliance. If you smell gas, evacuate immediately and call a professional. -
Power Cycle the Unit
-
Check Gas Supply Pressure
If you are not comfortable measuring gas pressure, call a professional. Gas leaks are dangerous. -
Inspect Gas Valve Wiring and Connections
Disconnect power before touching any electrical components. -
Replace the Main Gas Valve
Gas valve replacement requires purging the gas line and checking for leaks. If uncertain, hire a licensed technician.
Parts You May Need
Main Gas Valve
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Gas Valve Gasket Kit
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Main Gas Valve
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Gas Valve Gasket Kit
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Main Gas Valve
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Gas Valve Gasket Kit
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Main Gas Valve
Check Price on Amazon
Gas Valve Gasket Kit
Check Price on Amazon
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When to Call a Professional
If you are not comfortable working with gas lines or electrical wiring, or if error code 009 persists after replacing the gas valve, contact a Navien-certified technician. Also call a pro if you suspect a gas leak.Frequently Asked Questions
What does error code 009 mean on a Navien water heater?
Error code 009 indicates a main gas valve fault. The gas valve is not operating correctly, so the heater cannot ignite.
Can I reset Navien error code 009?
Yes, you can try a power cycle: turn off power and gas for 5-10 minutes, then turn them back on. This may clear a temporary fault.
How much does it cost to fix Navien error 009?
If the gas valve needs replacement, part cost is typically $150-$300. Labor by a professional can add $200-$400. DIY repair costs only the part.
Is it safe to use the water heater with error 009?
No, the unit will not heat water, and a gas valve fault could lead to unsafe operation. Do not attempt to use it until the issue is resolved.
What causes the main gas valve to go bad?
Common causes include power surges, age, debris in the gas line, or a faulty control board. Regular maintenance (e.g., cleaning gas filter) can help prevent failure.