Gas Water Heater (Tanked)
How your gas water heater works
Follow along with the diagram to understand how your gas water heater works.
A gas powered water heater has a cold water intake line bringing the supply of water into the tank through a part called a dip tube. This water is stored inside of the tank, and heated, in this case, by a gas burner located encased on the bottom of the unit. There are different size burners, depending on the size and model of your water heater, but the burner simply burns gas converting the energy to heat. The burning of the gas produces extremely hot carbon monoxide as a by product of the energy conversion process, and this is highly toxic. This Carbon monoxide air must be properly vented up through a chimney in the middle of the water heater tank and out through the vent pipe connected to the top of your water heater. The vent pipe directs this toxic gas outside the building, maintaining safety in your home.
Inside the water heater tank, the hot water rises to the top and the pressure from the incoming water supply line pushes the warm water out the top of the tank through the hot water line where it can be used in various locations in your home whenever you turn on the hot water faucet. The hot water stored inside the tank can be set to hotter temperatures by using the thermostat located on the unit itself. Setting the temperature higher, will result in hotter water, but it will also help you have more volume of hot water because for many activities, such as bathing and washing your hands, you will use a mixture of both hot and cold water. When the water temperature is higher, it will require less of the hot water, to reach the desired temperature, thus allowing you to have essentially more hot water at a given time. (This tip is great if you have guests come who want to take a shower. You can turn up the temperature and ensure there is enough hot water for a couple extra showers in the morning or night.) One of the main differences between a gas and electric water heater is the pilot light. The pilot light is a small flame that is constantly maintained ablaze. It ensures that whenever the creation of hot water is needed, the gas burner will have a lit and ready ignition source. Contrary to popular belief, an extinguished pilot light is not as dangerous as it sounds. There are fail safes that will stop the flow of gas when if it senses that the pilot light goes out. Natural gas is lighter than air, so if there is sufficient ventilation, there will not normally be enough concentration to combust upon ignition. That being said, if you smell gas, or notice that your pilot light has gone out, take precautions to ensure that there is not a build up of gas, before you attempt to relight your equipment. There are other safety measures built into the unit as well. The T and P valve, short for temperature and pressure release valve, is a protective measure that regulates the maximum pressure that can be maintained inside the tank. If the pressure becomes too great, the valve will open and release just enough to keep the tank from exploding and causing damage. The T and P valve is normally located on the top or the side of the unit, and not to be confused with the drain valve which will be located towards the bottom. The drain valve is for draining sediment, and removing water before relocating the tank. Proper maintenance is to drain your water heater for sediment at least one time per year. This will keep the performance up, furthering the life of the unit. Another crucial part of water heater maintenance is a part built to fail. It is called the anode rod. The anode rod is made out of a different material than the rest of the tank. A typical water heater is made of iron or steel, and if you paid any attention in chemistry class, or you ever left a bicycle outside in the rain, you would know that when it gets wet, it will rust. Rusting is simply the chemical reaction of oxidation. An anode rod is made up of aluminum, or magnesium, which will rust faster than iron. Because it rusts faster than the tank, it will essentially suck up and use up the loose oxygen atoms floating around in the tank and not allow the rust process to occur on the tank itself. Of course you will need to change the anode rod once it has completely rusted up, which is why it is suggested to check it during your annual sediment check. It is much easier, and cheaper to change the anode rod then to change the entire water heater. Pro tip, make sure to check and replace your anode rod every 2 years. Your home warranty insurance will not cover water heater replacement when damaged if the anode rod is not properly maintained.