Fixed a water heater in Suwanee this afternoon! Customer called reporting lukewarm water and occasional rumbling noises. Unit is a 6-year-old Rheem gas model. First checked thermocouple and gas valve - both working fine. Main issue ended up being severe sediment buildup in tank. Performed complete flush to remove accumulated minerals (water was seriously dirty!). Also found lower heating element heavily corroded, so replaced it with new one. Adjusted temperature setting to 120° for better efficiency and safety. While there, installed new pressure relief valve as preventative measure since original was showing signs of wear. Everything's running perfectly now with consistent hot water flow. Showed customer how to do basic yearly maintenance to prevent future sediment issues. They were super happy to have hot showers again!