American Water Heater water heaters use glass-lined steel with magnesium anode rod construction in their residential lineup. Annual maintenance follows standard residential tank practice — flush sediment, test T&P, inspect anode (every 3 years), and verify expansion tank charge. Below: the brand-specific schedule.
Annual maintenance — every year
1. Flush the tank
Sediment accumulates over time. Shut off power (electric) or set gas to "Pilot" (gas), attach garden hose to drain valve, do a partial 3–5 gallon flush. In hard-water areas (>7 grains per gallon), do a full drain-and-flush every 24 months instead of partial annually.
2. Test the T&P relief valve
Lift the lever fully for 1–2 seconds. Water should discharge briefly and stop cleanly. Continued dribbling indicates either pressure issues (verify expansion tank charge) or a failed valve — $20–30 replacement, 30-minute DIY.
3. Inspect for leaks
Visual check around all fittings, T&P discharge, drain valve, anode rod port, and base of tank.
4. Burner inspection (gas models)
Remove burner access panel. Look for spider webs, weak pilot, yellow burner flame (should be blue). Vacuum dust; clean pilot orifice if clogged.
Every 3 years — anode rod inspection
American Water Heater residential tanks use a 3/4" NPT magnesium anode rod (some lines offer aluminum-zinc for sulfur-water areas). Pull and inspect: original full diameter = good, 75% consumed = replace. Replacement anodes are standard size — universal aftermarket flexible anodes ($45–65) or rigid ($25–35) fit.
Every 5 years — preventive replacements
- Replace anode rod proactively if not already done — doubles tank life expectancy
- Replace T&P valve preventively ($20–30)
- Inspect dip tube — cracked dip tubes cause "hot water runs out fast" symptoms
- Verify expansion tank charge (pressure-gauge test; charge to 5 psi below incoming water pressure)
American Water Heater-specific notes
American Water Heater units are mid-tier residential brand manufactured by A.O. Smith Corporation (American Water Heater Company is a subsidiary brand). Underlying manufacturer is A.O. Smith (parent company), so part numbers and warranty paths may route through that manufacturer rather than American Water Heater customer service directly. Save your model number and the data plate photo for future reference.
Common maintenance mistakes
- Skipping annual flush in hard-water areas — sediment shortens tank life by 3–5 years
- Forgetting expansion tank charge verification — lost pre-charge causes T&P weeping
- Powering on dry-fired electric elements — destroys elements in seconds, voids warranty
- Over-tightening anode rod port — cracks the porcelain coating around the threads