How to Maintain Your Gas Tankless Water Heater for Longer Life
A gas tankless water heater delivers endless hot water, high energy efficiency, and long-term savings. However, to achieve a lifespan of 15–20+ years, proper and consistent maintenance is essential. This guide explains how to maintain a gas tankless water heater to improve performance, prevent breakdowns, and extend its service life.
Why Gas Tankless Water Heater Maintenance Is Important
Gas tankless water heaters rely on advanced burners, heat exchangers, and control systems. Over time, mineral scale, debris, and combustion residue can affect efficiency and safety.
Benefits of Regular Maintenance
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Extends gas tankless water heater lifespan
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Maintains stable water temperature
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Improves energy efficiency
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Reduces repair costs and error codes
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Helps maintain manufacturer warranty
Annual Maintenance Tasks for Gas Tankless Water Heaters
Flush and Descale the Heat Exchanger
Mineral buildup is the most common cause of reduced performance in gas tankless water heaters, especially in hard-water areas.
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Flush the unit once per year (every 6 months for hard water)
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Use white vinegar or an approved descaling solution
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Circulate the solution for 45–60 minutes
Regular descaling improves heat transfer and prevents premature heat exchanger failure.
Clean the Inlet Water Filter
The inlet filter protects internal components by trapping sediment and debris.
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Turn off gas, water, and power
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Remove and rinse the filter with clean water
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Reinstall securely before restarting the unit
Clean the filter every 3–6 months for optimal performance.
Inspect and Clean the Burner Assembly
A clean burner ensures efficient combustion and reliable ignition.
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Inspect annually for dust, lint, or soot
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Use compressed air or a soft brush for cleaning
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Contact a professional if corrosion or heavy buildup is found
A dirty burner can lead to ignition failure and temperature instability.
Safety Checks for Gas Tankless Water Heaters
Check the Venting System
Proper venting is critical for both performance and safety.
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Inspect vent pipes for leaks, corrosion, or disconnections
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Ensure no obstructions such as debris or nests
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Confirm venting meets local building codes
Improper venting can result in carbon monoxide hazards and should be addressed immediately.
Monitor Error Codes and Performance Issues
Modern gas tankless water heaters display error codes when problems occur.
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Refer to the user manual to identify error codes
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Address recurring codes promptly
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Watch for warning signs such as fluctuating temperatures or reduced hot water flow
Early intervention can prevent costly repairs.
Professional Gas Tankless Water Heater Maintenance
Schedule Annual Professional Service
While basic maintenance can be done by homeowners, professional servicing is recommended once per year.
A qualified technician will:
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Test gas pressure and combustion efficiency
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Inspect the heat exchanger
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Verify safety sensors and valves
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Confirm proper venting operation
Professional maintenance helps ensure safety, efficiency, and long-term reliability.
Best Practices to Extend Gas Tankless Water Heater Lifespan
Keep the Installation Area Clean
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Maintain proper airflow around the unit
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Keep flammable materials away
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Ensure service valves are accessible
Use Water Treatment Solutions
Installing a water softener or scale inhibitor reduces mineral buildup and decreases the frequency of descaling.
How Long Does a Gas Tankless Water Heater Last?
With proper maintenance:
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Average lifespan: 15–20 years
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Well-maintained units: 20+ years
Routine care significantly improves both lifespan and energy efficiency.
Final Thoughts on Gas Tankless Water Heater Maintenance
Maintaining a gas tankless water heater is the key to reliable performance, energy savings, and long-term value. Annual flushing, regular inspections, and professional servicing will help your system deliver consistent hot water for years to come.
Investing time in proper maintenance today can prevent costly repairs and extend the life of your gas tankless water heater well into the future.
