Your Complete Guide To Water Heaters: How They Work, When and What Kind to Buy
Whether your water heater is failing or you’re building a new house and need a new water heater installation, there’s a lot to consider before making your purchase.
In this article, you’ll get the lowdown on water heaters so you’ll be more informed when you go to your big box hardware store or plumbing supply store.
How Does a Water Heater Work?
Most conventional water heaters comprise a tank that holds water, which is heated by a fuel source — either electricity or gas. Recently, tankless water heaters have come onto the scene and are growing in popularity, but we’ll touch on those later.
Gas Water Heaters
For now, let’s look at the conventional gas water heater. These water heaters are made up of several parts including the dip tube, the gas burner, the gas chimney, a vent shaft, the heat out pipe, the thermostat, the T&P valve, the drain valve, insulation, and the anode rod.
For this water heater to work, cold water is brought into the tank through the dip tube, which is then heated by the gas burner. As the gas burns, it creates hot, toxic air, which flows through the chimney running through the middle of the tank. This hot air flows through the chimney and heats the metal, which heats the water in the tank. The toxic air continues to flow up the chimney and outside of the house.
Since heat rises, your water heater uses this principle to provide the hot water to your home’s plumbing system via the heat out the pipe. So, when you turn on your faucet, the cold water comes in through the dip tube which displaces the hot water in the tank and pushes it out through the heat pipe and eventually out of your faucet. You can set how hot your water gets via the thermostat on the hot water tank which tells the burner hot much gas to use to bring the water to the desired temperature.
Since this tank contains hot water under pressure, there are safety measures in place to protect your tank and your home from an explosion. Modern water heaters have pressure relief valves or the T&P valve which opens and releases water if the pressure gets too high. Also, modern water heaters have a drain valve to facilitate draining the tank to combat the buildup of sediment, which can shorten the lifespan of the heater.
The electric water heater works the same way as the gas water heater except for the fuel source, which is electricity.
A Word About Tankless
So, what about tankless? Tankless or on-demand water heaters as they’re sometimes known, are becoming more popular among homeowners.
As the name implies, tankless water heaters don’t rely on a tank full of water that’s heated up by gas or electricity; instead, these units pull in cold water and heat water directly either via a gas burner or electric element.
The advantage of a tankless water heater is they provide instant hot water for as long as you want — there’s no danger of running out of hot water like you can with a traditional tank water heater.
The downside to most tankless water heaters is their inability to provide multiple streams of hot water at once, which can be tough for someone with a large family who needs hot water all at the same time. The workaround to this is to install multiple tankless systems throughout the house, but they’re typically more expensive than traditional tank water heaters.
Last, let’s look at solar water heaters, which are also growing in popularity thanks to people becoming more conscious about the environment.
Solar water heaters come in a variety of designs, but two main types: Active and Passive. The active solar water heater has either direct or indirect circulation. Direct circulation means a water pump pumps water through collectors while indirect systems don’t pump water through collectors and instead pump fluid through the collectors to be heated which in turn heats the water that rests in a storage tank. The collector portion of the system pulls in the heat from the sun and heats the water.
While solar water heaters are great for the environment and cut down on your carbon footprint, you run into the same problem as with tank water heaters, which is the possibility of running out of hot water.
Pros & Cons
Now we’ve learned about the different water heaters, what are the pros and cons of each?
Traditional water heaters are standard, easy to install, and relatively inexpensive. They’re great for providing multiple streams of hot water throughout the house, so you can take a hot shower and run a cycle through the dishwasher at the same time.
The downside of traditional systems is the possibility of running out of hot water, which can be an issue if you have a large family with heavy demands for hot water. Also, tank-style water heaters don’t last long — about 12-15 years.
Tankless water heaters are perfect for the family who needs instant hot water and doesn’t want to worry about ever running out. They’re small and fit perfectly in any sized home whereas tank water heaters are large and cumbersome.
The cons of tankless water heaters are the expense — a typical installation can run between $1,500 and $2,000, which is high compared to a tank water heater which can be installed for about $600. Also, tankless water heaters have difficulty supplying multiple streams of hot water at a time, however, if you have the budget, installing various tankless units is a great way to ensure everyone has as much hot water as they want when they want it.
What to Consider When Buying a Water Heater
Now you’ve decided you need a new water heater, what should you keep in mind before you head to the hardware store?
First, decide on the water heater that best suits your needs, whether it’s a tankless water heater or a standard one.
If you’re purchasing a standard water tank, consider the tank size because they come in many varieties, and the last thing you want is to get a unit that’s too small for your family, and you end up running out of hot water frequently. A good rule of thumb says to get 40 gallons for every 1 to 4 people in your home, 50 gallons for 4 to 6 people and 75 gallons for 6 to 8 people.
Also, consider the fuel source. If you have access to both electricity and gas, go with what’s cheaper. And, for saving money, look for a water heater that’s a high-efficiency unit, which saves you money every month on your energy bills. To ensure the unit lasts a long time, look for a water heater that has a good warranty. Most times, you can find one with warranties that run from 6 to 12 years.
Lastly, look for a water heater that fits your budget.
Hot Water Heater Maintenance & Longevity
Since a hot water heater is an expensive investment, you want it to last as long as possible, and to do that, it’s essential you perform regular maintenance on yours to ensure it remains efficient and lasts a long time. Here are a few things to do to keep your hot water heater running well.
- Flush the tank to reduce the buildup of sediment that causes premature failure and water line clogs.
- Check the pressure valve to make sure it’s functioning properly.
- Check the anode rod for corrosion and replace it if it’s corroding or if it’s covered with calcium.
- Maintain your water heater’s insulation. Keeping your water heater well-insulated keeps the water hot and ensures the unit doesn’t have to work as hard, which extends its lifespan.
- Call in a professional plumber every three years for an inspection and to find small problems before they turn into larger ones down the road.
How to Calculate Energy Costs
Everyone wants to save money, especially on their home’s energy bill. A great way to do that is to know how much energy your major appliances use and select the models that are the most efficient. The average water heater uses about 4000 watts per day of fuel. To calculate how much the average water heater costs you in energy, take the number of hours your water heater is used per day and multiply that by the watts used to get the price per kilowatt. There are many free energy calculators online to help you determine this if you don’t feel like doing the math yourself.
Water heaters are a necessity in today’s home, and fortunately, you can find a unit that fits your family’s needs and your budget easily. Keep in mind that while performing maintenance on your water heater is a chore, it’s essential to keep the unit running smoothly for years with no sudden failures that leave you without hot water for days.