First of all we need to make a point of clarification. There are no "Code Free" areas. There are some regions where the codes are adopted by the local AHJ (authority having jurisdiction; I.E.-Municipality, township or county) and in some areas within that region the local AHJ has not officially adopted a code, nor do they require permits or inspections, however; all States have a code, and in the absence of a local code, the state code has jurisdiction. One example of this practice is the State of Ohio. In many jurisdictions within the state of Ohio there are no permit requirements or inspections (with the exception of septic tanks) for building a "Single Family Dwelling intended as the primary domicile of the owner/builder." Pay special attention to that phrase "intended as the primary domicile of the owner builder". The exception to code inspections only applies so long as the owner/builder or members of his/her immediate family solely occupy the structure. In turn, the original "certificate of occupancy" reflects that this is an "Un-inspected domicile" and should you decide to sell or rent the property to a third party the state reserves the right rescind the original CO and they may compel a complete code inspection before you may be issued a CO to transfer title or possession.

There are minerals and traces of other chemicals in your water. When the water is heated, they get together with any exposed metal in your tank and form precipitates. These are solid paricles which fall to the bottom of the heater, where the burner is. As they collect, they form a layer across the bottom. This layer becomes thicker over the years. By the time you start to notice hot water shortages, this layer is probably a good five to ten inches thick. The higher you turn the temperature, the faster the precipitate forms. The anode rod is a sacrificial piece of metal which dissolves more readily than the steel tank. It lasts around three years. Your hw tank is lined with glass. But the seam on the side of the tank is welded after the tank is lined, and so the glass melts. So, to make the heater last a long time, drain it once in a while, change the anode rod once in a while, and keep the temperature low. There are only three manufacturers of residential water heaters in the US: Rheem, State, and A.O.Smith. All others have contracts with these manufacturers. Read the fine print on the label on the water heater. They have all been in business for a long time. If one is worse than another, it won't stay that way for long, because it will lose business. State has a patent on a special fill tube that circulates the water and keeps precipitate in suspension, but big bucks. State has sued other manufacturers for infringement and won. Otherwise, as far as I know, they are all pretty much the same.

coolvt, "So, is the theory that without a check valve, the expanded water is forced back into the supply from the street? Therefore, no expansion tank is needed?" That is correct BUT somewhere in the 90's the law (code) was changed to prevent the backflow of potable water from a house back into the water system eliminating the possibility of contaminating the water system by backflow from a house. I believe that all new contruction from that point mandated a check valve. The check valve can be unique or incorporated into a PRV (pressure reducing valve) or in a water meter. You may not even know that you have a check valve making your house a closed plumbing system. To be safe, buy a Watts IWTG at Home depot. It's a pressure gauge with a red tattletale needle that sticks at the highest pressure. You can screw it right on to a hose bib or the drain valve on your water heater. If you use the drain valve on your WH there's a chance the valve may leak when you're done if you haven't been routinely draining your WH. If there's a pressure spike due to thermal expansion you'll see the needle up at 120lbs or higher. Watts IWTG gauge here If you see those high pressures then you'd better get on the horn with a plumber or fire up the torch. Where I live they added check valves as meters and PRVs were replaced. Code for new construction here now mandates two unique forms (methods) of thermal expansion control usually resulting in the installation of an expansion tanks and something like a Watts GOV-80 toilet ballcock or a Watts BRV (combination ball and pressure relief valves).

What he said^^^^^^^,you must continue holding the button down for time stated next to button. If it still gos out,make sure the flame is touching tip of thermocouple. Thermocouple is a wire 3 times diamiter of a round tooth pick leading from near the button to piolet liight. If flame is touching,thermocouple has likly burnt out. Very common. It is inexpensive,available at most hardware stores and can be replaced by average home handyman.