You should flush an A.O. Smith water heater at least once a year to remove sediment buildup and maintain efficiency and longevity.
Flushing your AO Smith water heater is one of the most important maintenance tasks to ensure longevity and efficiency. Sediment buildup can reduce performance, increase energy bills, and even cause premature failure. This guide covers everything you need to know about flushing frequency, signs it’s needed, and step-by-step instructions.
Why Flushing Your AO Smith Water Heater Matters
Mineral deposits and sediment naturally accumulate in water heaters over time. Hard water areas see faster buildup. This sediment settles at the bottom of the tank, creating several problems:
- Reduces heating efficiency by acting as an insulator between the burner/element and water
- Can cause overheating of tank components leading to failure
- May create strange noises (popping, rumbling) as sediment moves
- Can discolor water and affect taste
- Shortens the lifespan of the unit
Regular flushing removes this sediment before it causes damage. It’s one of the simplest ways to extend your water heater’s life.
Recommended Flushing Frequency for AO Smith Water Heaters
Standard Recommendation
AO Smith recommends flushing tank-style water heaters at least once per year. This applies to both gas and electric models. Annual flushing prevents significant sediment accumulation in most households.
Adjustments for Hard Water
If you have hard water (water with high mineral content), increase flushing frequency to every 6 months. Hard water causes faster sediment buildup. You can test your water hardness with simple test strips available at hardware stores.
Tankless Water Heaters
Tankless models don’t require flushing like tank-style heaters. However, they need annual descaling to remove mineral deposits from heat exchangers. Follow the manufacturer’s descaling instructions for your specific tankless model.
Signs Your Water Heater Needs Flushing
Watch for these indicators that your AO Smith water heater needs flushing before the scheduled maintenance:
- Rumbling or popping noises from the tank
- Reduced hot water supply
- Longer recovery times (takes longer to reheat)
- Rust-colored water
- Visible sediment in faucet aerators
- Higher than normal energy bills
If you notice any of these signs, flush your water heater immediately regardless of when you last performed maintenance.
Step-by-Step Guide to Flushing an AO Smith Water Heater
Preparation
- Turn off power to the unit (circuit breaker for electric, gas valve for gas models)
- Allow water to cool for several hours (prevents scalding risk)
- Shut off cold water supply to the heater
- Gather supplies: garden hose, bucket, gloves, goggles
Draining Process
- Connect hose to drain valve at bottom of tank
- Route hose to floor drain or outside area
- Open a hot water faucet in home (relieves pressure)
- Open drain valve and allow tank to empty completely
- Briefly turn cold water supply back on to flush remaining sediment
- Repeat until water runs clear
Restarting the Unit
- Close drain valve and remove hose
- Turn cold water supply back on
- Allow tank to fill completely (verify by opening hot water faucet until steady stream)
- Restore power to the unit
- Check for leaks at all connections
Additional Maintenance Tips
Combine flushing with these other maintenance tasks for optimal performance:
- Anode rod inspection: Check annually and replace when 50% depleted
- Temperature and pressure relief valve test: Lift lever annually to verify proper operation
- Thermostat check: Verify temperature setting (120°F recommended)
For complex maintenance or if you’re uncomfortable performing these tasks, consider hiring a professional. HVAC technicians have specialized tools that make the job easier.
Water Heater Replacement Considerations
Even with proper maintenance, water heaters eventually need replacement. Signs it’s time for a new unit include:
- Age over 10 years
- Frequent repairs needed
- Visible rust or leaks
- Insufficient hot water despite maintenance
When replacing, consider energy efficient models that can save on operating costs. AO Smith offers high-efficiency options with longer warranties.
Professional vs DIY Flushing
While many homeowners can flush their water heater, professional service may be better if:
- You’re uncomfortable working with plumbing systems
- The unit hasn’t been flushed in several years (heavy sediment)
- You notice signs of serious corrosion
- The drain valve is stuck or leaking
Professionals have commercial-grade pumps that can remove stubborn sediment more effectively than standard draining. They can also inspect other components like the anode rod and heating elements during service.
For more information on maintaining home heating systems, check out this guide from the U.S. Department of Energy.
Remember that proper maintenance like regular flushing can double the life of your water heater. As noted by American Home Shield, neglecting this simple task leads to thousands of premature water heater replacements each year.