Hello. I live in a single-family home in Chicago. I have lived in this home for 35 years. Our home's water heater was here when my family bought this home. So, this water heater is at least 35 years old. Our water heater is a RheemGlas Fury, model # 22-40-2. The water heater has 40 gallons and 45000 BTUs. This water heater has been making weird noises for months. Because of the noises and the water heater's age, I think that it's time to buy a new water heater. I have read a lot of bad things about Rheem and Richmond water heaters. So, I have ruled out those two brands. I have read a lot of good things about A.O. Smith and Reliance water heaters. I have also read some bad things about the A.O. Smith and Reliance brands. In Chicago, there is a store called Lowe's. This store sells A.O. Smith water heaters. An installer from Lowe's came to my home, did some measurements, and gave me an estimate. The installer recommended the following water heater: A.O. Smith, model # G9-T4040NV https://www.lowes.com/pd/A-O-Smith-...40000-BTU-Natural-Gas-Water-Heater/1000213613 In Chicago, there is also a store called ABT Electronics. This store sells Reliance water heaters. One Reliance water heater is the following: Reliance, model # 640NBRBT https://www.abt.com/product/93178/Reliance-40-Gallon-Tall-Natural-Gas-Water-Heater-640NBRBT.html My first question is, which brand is better? A.O. Smith or Reliance? My next questions concern water-heater maintenance. I have read that current water heaters require the following maintenance: 1) periodically flushing the tank 2) periodically checking the anode 3) periodically cleaning the air filter at the bottom of the water heater I asked a Lowe's employee about maintenance, and he said that this maintenance is optional. In the 35 years that we have lived in this home, we have never even touched the RheemGlas Fury water heater. So, I prefer a water heater that requires very little to no maintenance. So, was the Lowe's employee correct? Is maintenance optional? Is there any water-heater model that requires very little to no maintenance? Thank you.