If you’re needing to have your existing water heater replaced, it is important that you carefully consider all of the available options. The energy efficiency of a water heater is obviously an important thing to think about, and you will also want to consider how long your new water heater should last. To make this easier, here is an overview of which types of water heaters will last the longest and also other factors that may influence your decision on which type of water heater you want to purchase.
Average Lifespan for Different Types of Water Heaters
In most homes, your options are a traditional tank-style water heater, a tankless unit, or an electric heat pump water heater. If your home has a boiler and radiant heating, you can also opt for an indirect water heater that relies on the boiler to heat the water inside of the tank.
Tank-style water heaters generally always have the shortest lifespan of any type of unit. A gas-burning tank water heater will typically last for somewhere between eight and 12 years at the very most. Electric tank units typically have a slightly longer lifespan and may last for around 12 to 15 years. A new electric heat pump water heater will usually also have a similar lifespan and may last for up to 15 years. The main reason that all of these units will only ever last for a maximum of 15 years is that they all have a steel tank that slowly corrodes over time and can eventually weaken to the point where the tank starts to leak.
Tankless water heaters have many advantages over traditional tank-style and heat pump water heaters, and this is especially true when it comes to average life expectancy. A new gas or electric tankless water heater will typically last for a minimum of 20 years, and some units may last for 30 years or more. Tankless units typically cost at least a few hundred dollars more than a traditional gas or electric tank unit. However, this high initial cost is offset by the fact that a tankless unit may last twice as long as a tank unit.
Comparing Energy Efficiency
Energy efficiency is another important factor to consider since it will dictate how much your water heater costs to operate each month. Gas-burning tank water heaters are the least energy efficient. Electric tank water heaters are slightly more energy efficient than gas units. However, gas units will usually cost a bit less to operate, and this is simply because natural gas rates tend to be cheaper than electricity.
Electric heat pump water heaters are typically the most energy efficient, but this can depend on where you live and where the unit is installed. Heat pump water heaters work by using refrigerant to capture heat energy from the surrounding air. The refrigerant then passes through an expansion valve that instantly transforms the refrigerant from a hot liquid into an even hotter gas. The hot refrigerant then travels through a series of coils in the water heater tank, and the heat is released from the refrigerant to raise the temperature of the water in the tank.
When installed in an area of the home that never gets too cold, heat pump water heaters will typically use much less energy than any other type of unit. However, most heat pump water heaters are hybrid units that also contain electric heating elements. If the temperature of the surrounding air is too cold or the water in the tank is far below the desired temperature setting, the unit will switch and use the electric heating elements. If the unit has to rely on the electric heating elements frequently, then its energy efficiency will decrease by quite a bit.
The energy efficiency of gas and electric tankless water heaters is typically slightly less than heat pump units. The only exception is if a heat pump unit needs to rely on its electric heating elements often; in this case, a tankless unit may be slightly more efficient. Compared to tank water heaters, tankless units are typically quite a bit more efficient. The main reason is that tank units waste lots of energy since they need to occasionally reheat even when no hot water is being used.
Tankless water heaters are different as they only turn on and heat on demand when hot water is currently needed. As soon as you open a faucet or turn on the shower, the unit will immediately turn on and the water will be heated to the desired temperature within a few seconds. The fact that tankless units heat on demand means that their energy usage is entirely dictated by how much hot water you use.
If your family typically uses less than 40 gallons of water on an average day, a tankless water heater will usually use around 40% less energy per month than a tank unit. If you usually use 80 or more gallons of hot water in a day, your energy savings with a tankless unit may only be around 10% less than with a tank unit.
Maintenance is another area where tankless water heaters reign supreme. All tank units, including both traditional and heat pump water heaters, always need to be fully drained and flushed once or twice a year. Flushing is important for removing all of the sediment that naturally forms in the tank when the water is heated. If the unit isn’t flushed regularly, the sediment can lead to hot spots forming that can weaken the tank and speed up the rate at which it corrodes.
Sediment can also prevent the unit from heating efficiently as it can coat the electric heating element or absorb much of the heat from the gas burner. If a tank unit isn’t flushed regularly, it will eventually need to run for much longer and have a shortened lifespan.
Tankless water heaters don’t have issues with sediment since they don’t store hot water. The units should still be flushed and cleaned every year or two to prevent limescale build-up, but the process of flushing a tankless unit is much easier and quicker.
Another issue with all tank water heaters is that you need to have the anode rod inspected regularly and replaced as needed. The anode rod works to prevent minerals in the water from reacting with and corroding the steel tank. To prevent the tank from being corroded, the anode rod sacrifices itself so that the minerals corrode it instead.
As a result, the anode rod will typically need to be replaced every three to five years. If you don’t have the rod inspected regularly and replaced when needed, the tank will corrode more quickly and the unit won’t last nearly as long. This is obviously not an issue with tankless units since they don’t need anode rods.
Expert Water Heater Services
At Environmental Heating & Air Solutions, we carry an extensive selection of water heaters, including tank, tankless, and hybrid units, and our team can help guide you through the different options so you can make a more informed decision on which unit is best for your home. For more information on our water heater installation services in Vacaville, or to schedule a consultation for any plumbing, heating, cooling, or air quality services, contact us today.