Figuring out the best water heater to buy may be more complicated than first meets the eye. Although a water heater has a very simple function, there are a number of factors that will affect your decision.
Considering this is something you go out and buy about once a decade and the available options keep increasing, you should find this overview worth your time.
Buying a water heater doesn’t have to be confusing. After considering factors such as natural gas or electric, tank or tankless, sizing, and both the up-front cost and the cost to operate, you can find the best water heater for your home.
Do I Need to Replace a Water Heater?
If you’re asking that question, the answer is probably yes, and it’s especially true if you don’t know how old the water heater is in your home. The conventional water heater with a tank, which is the most common type in the United States, has an average life span of 8 to 12 years.
As a water heater ages, it loses efficiency, so replacing an older model can be a wise choice. Water heaters wear out with normal use, but you can slow down the aging process. Here are the most common conditions to watch for.
Sediment buildup – minerals in water separate under heat and settle to the bottom of the tank. If not drained at least annually, the sediment can build up to depths of a foot or more, leaving less space for hot water. Furthermore, sediment deposits can cause the lower heating elements in electric water heaters to fail, and they can create hot spots in gas water heaters that stress the tank. In some cases, sediment will clog the drain valve when you attempt to drain it from the tank and keep the valve from closing completely. Rumbling or popping sounds coming from the tank indicate significant sediment buildup. Homes with hard water are especially susceptible to sediment buildup, even in the best water heaters.
Anode rod corroded – when different types of metals are connected in water, as happens in water heater tanks, galvanic corrosion results, eating away at the most vulnerable metals. For this reason, steel water heater tanks have a “sacrificial” anode rod that is made to corrode instead of the steel tank. An anode rod may last as long as four or five years but should be checked annually for corrosion. The adjacent image shows new and corroded anode rods. When the rod is covered extensively it has been “sacrificed” and must be replaced. Otherwise, the tank will begin to corrode and ultimately fail. Rust in your hot water is a good indication the anode rod is not working and the tank has begun to rust.
High water pressure – water pressure in most homes runs from 40-to-80 pounds per square inch. Higher pressures are not unknown, but as a rule of thumb, the higher the water pressure the more stress it places on a home’s entire plumbing system. Water heaters with tanks are especially vulnerable when tanks are full. If there is no expansion tank or if the temperature and pressure relief valve is damaged, the tanks must withstand extra pressure. In worst cases, the tank can explode and cause serious damage to a home. If you frequently see water coming from the overflow pipe your water pressure may be too high.
Wrong size water heater – you can buy the best water heater on the market, but if it’s too small to supply all the hot water your home needs it will work overtime trying to keep up. Water heaters designed for a home with two people will be stressed serving three or more. Constant running will cause the heater to wear out before its expected lifespan of 8 -12 years.
Corrosive fumes – not as common and often overlooked is that propane and natural gas water heaters require a good air supply to support combustion. If the air quality around the water heater is poor – such as having bleach fumes in the air from a nearby washing machine – the bad air causes corrosion in the water heater and can lead to premature failure.
Tankless water heaters are not immune – water conditions that cause sediment buildup in water heaters with tanks can cause the mineral scale to build up in tankless water heaters. Calcification in the heating element can prevent good heat exchange and cause the element to overheat. This also can clog the outbound hot water line and reduce water pressure. Occasionally, a water leak will develop in the heat exchanger and cause corrosion that can lead to catastrophic failure and serious damage to your home.
There are some clear signs of trouble with a water heater that you should look for, including the obvious one — insufficient hot water. You should also be concerned if the water heater is making popping or banging noises, is producing water that is cloudy or has a bad odor, or has a tank that is leaky.
Water heater service is especially important for older models, but all water heaters work best when they are properly maintained. More on that below, but before that, let’s talk about what to consider when buying the best water heater for your needs.
It Starts with the Fuel: Natural Gas or Electric
There are actually several more fuel options than natural gas or electric, including geothermal energy, propane and solar, but we’ll focus on the most common ones. Electricity is available in all homes, and natural gas is available in many, so options are plentiful for electric and gas water heaters.
If you already have an electric water heater, sticking with electricity will keep your installation costs down. But if your home has electricity and natural gas as fuel sources, it’s good to know that natural gas is typically cheaper than electricity. Natural gas water heaters are a little more expensive than electric water heaters, but gas heaters can make up the difference in price in about a year.
Comparing Water Heaters with Tanks and Tankless Water Heaters
The most obvious difference is made clear by their names: one has a tank that stores water and the other does not. But you’ll need more details to know whether tank or tankless is the best water heater for you.
Conventional Water Heater with Tank
A water heater with a tank holds between 30-50 gallons of water – some models are even larger — that is stored until hot water is needed.
- Pros: Less expensive to purchase and install than a tankless water heater; available in a wide range of sizes. The insulated tank allows it to provide hot water in cases of a power outage, as well as an emergency water supply if water service is interrupted.
- Cons: The best water heaters with tanks have shorter life expectancy (8-12 years) than tankless water heater (20 years or more); more expensive to operate because of need to heat and reheat a large volume of water so it’s always ready; amount of available hot water limited by size of storage tank; risk of water damage to home if tank leaks or ruptures.
Tankless Water Heater
Instead of storing hot water, a gas burner or electric element heats water as it flows through a pipe and then delivers that hot water to where it’s needed in the home.
- Pros: According to the U.S. Department of Energy, a tankless water heater can be 34 percent or more energy-efficient than a conventional water heater with a tank, cutting utility bills considerably. Tankless water heaters also have a life expectancy of more than 20 years, take up less space and can provide immediate hot water (no waiting for the water to warm up).
- Cons: More expensive to purchase and install; flow rate (the amount of water that can be heated in a minute) on some models might not provide enough hot water during heavy usages, such as two showers at once, but that is not a problem if you purchase the right size tankless heater.
Ask How Much Hot Water You Need to Determine Best Water Heater Size
As we talk about how much hot water you’ll need, it’s important to bring up the National Appliance Energy Conservation Act, which in 2015 called for improved water heater efficiency. The result is that water heater tanks are now larger to provide better heat retention — without an increase in storage volume.
The increased size, generally at least two inches taller and two inches wider is due to added insulation. If you’re replacing a water heater with a tank in a fairly tight space, that’s something to consider. Tankless water heaters require far less space than nearly any water heater with a tank.
Water Heater with Tank: Look for the first-hour rating (FHR), which is the gallons of hot water that can be supplied per hour, starting with a full tank of hot water. It’s important to note that a large tank does not necessarily translate to a higher FHR because some models with smaller tanks have a faster recovery rate. In some cases, a home needs more than one water heater, as with this installation in a larger home.
The first-hour rating is listed on the EnergyGuide label, which the Federal Trade Commission requires on all new storage tank water heaters. The Department of Energy offers a simple worksheet to help estimate the best water heater size for you. Gas water heaters heat water faster than electric ones, so you may need a bigger size if you choose electric.
Tankless Water Heater: Gallons-per-minute flow rate is the key to properly sizing a tankless water heater. Gas-fueled tankless systems are typically more efficient than electric ones, and they also heat the water faster. For a home with only one or two people, an electric system might suffice, but for a home with a family of four or more, a gas-fueled tankless heater will handle the demands far better.
Like with a water heater with a tank, calculating the peak hot-water demand in your home is a good first step toward finding the right tankless unit. A licensed plumber can also help you weigh the options.
Water Heater Maintenance to Optimize Performance and Longevity
Regardless of what you decide is the best water heater for you, proper water heater maintenance is important to make sure your system is operating at maximum efficiency. Proper maintenance also prolongs the life of your water heater, getting you more return on your investment.
There are a few maintenance tasks with a water heater with a tank that a certified plumber can perform, but you might also be able to try on your own:
- Check the pressure relief valve: If too much pressure builds up in the water heater tank, it can explode. When working properly, the pressure relief valve automatically opens to relieve the pressure. To test it, pull up gently on the lever on the top of the pressure relief valve to see that water is released through the overflow tube.
- Flush the tank: Over time, sediment can build up on the bottom of a water heater’s tank. It reduces the efficiency of your water heater and can make it break down prematurely. Make sure you turn off the power source to your water heater before beginning the flushing process.
Always remember that safety comes first, so wear gloves and protective goggles when working with your water heater. If you’re at all uncertain about how to perform a maintenance task, or you suspect there’s a problem with your water heater, consult a licensed plumber.
Mineral buildup can also be a problem for tankless water heaters. Using undiluted white vinegar is one way to remove limescale, the calcium carbonate and residue left behind by hard water.
Everyone needs a hot water heater, but the same water heater won’t fit the needs of everyone. That’s why you should educate yourself to make the best water heater choice that considers all your options. Once you know what is available, you can decide on gas or electric, tank or tankless, and the size of the unit that is right for you. How long you plan to live in your current home might help you determine whether a higher up-front cost is worth years of lower utility bills.
Whatever you decide is the best water heater for your needs, you can feel good that it will be more efficient than your previous model because of updated technology and the Department of Energy’s increased efficiency standards. A more efficient model can take a nice chunk out of your utility bills, considering water heating accounts for about 18 percent of the typical home’s energy use.
So are you ready to lower your utility bills — and help the environment at the same time?