Hot Water Heater Buying Guide

Things to Consider Before Purchasing a Water Heater

Purchasing a new hot water tank is an important decision. In addition to choosing an energy-efficient water heater, you need to decide between tankless versus tank models and choose one that meets the hot water needs of your home and family. To take the guesswork and frustration out of the process, determine what you need before you go shopping. Household needs to consider include:

Fuel source
Type of heater
Capacity
Space requirements
Water heater size

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Tip

Not sure when to replace your water heater? Our article, How to Decide Between Water Heater Repair or Replacement, will help you make the right choice.

It’s also a good idea to plan ahead and research water heater options, technologies, operating costs and installation requirements before your existing unit fails.

What Types of Fuel Do Water Heaters Use?

First, find out what type of fuel source is in the home. Here are the differences between electric, gas/propane and hybrid fuel types.

Electric Water Heaters

Many full-size electric water heaters use a dedicated 240-volt circuit, but electrical requirements vary by model.

When comparing a gas water heater versus an electric water heater, an electric model may offer a lower upfront cost and easier installation. Potential disadvantages include susceptibility to power outages, slower heating times and higher average operating costs.

An electric hot water heater is a practical choice for homes that don’t have access to natural gas or propane. Before selecting one, make sure your electrical system meets the model’s installation requirements.

See How to Install an Electric Water Heater for more information.

Gas or Propane Water Heaters

A gas water heater uses a burner to heat water and ranges in size from 30 to 100 gallons. These units require proper ventilation and adequate clearance from combustible materials. Gas or propane water heaters are typically more expensive than electric water heaters.

A gas hot water heater may cost more upfront than an electric hot water heater, but overall operating costs depend on local utility rates, efficiency and household hot water use. If you’re comparing an electric water heater versus gas, consider more than the purchase price. Also consider installation requirements and energy costs.

Here are useful tips on How to Install a Gas Water Heater.

Heat-Pump or Hybrid Hot Water Heaters

Heat-pump water heaters use electricity to transfer heat from the surrounding air into the water rather than generating heat directly. This can significantly reduce energy use and operating costs compared with a standard electric water heater. An ENERGY STAR™ certified heat-pump water heater can save a family of four approximately $600 per year on energy costs compared with a standard electric model. Many models also offer convenient features such as digital controls, vacation modes, leak detection and Wi-Fi connectivity.

However, heat pump water heaters typically have a higher upfront cost and may require additional installation space, airflow and condensate drainage.

Tip

Local utilities may offer rebates and incentives on some types of high-efficiency water heaters. Check with your utility provider to see what’s available and browse current water heater rebate offers at our rebate center.

Types of Water Heaters

Water heaters come in several types, each with different benefits and features. Understanding your options can help you choose the right water heater for your home.

Storage tank water heaters are the most common. They’re available in electric models as well as natural gas and liquid propane models. They heat water and store it in an insulated tank until you need it. To get an estimate of the energy efficiency and yearly operating costs of each model, look at the product label in the store or product description online.

When comparing tankless versus tank hot water heater options, keep in mind that traditional tank models store a set amount of hot water and come in a range of sizes. Check the EnergyGuide label or online product information to compare estimated energy use and annual operating costs.

Advantages of these water heaters include flexible sizing that fits in both large and compact spaces. Electric models can be energy-efficient in all climates, and the repair and replacement costs are relatively low. Additionally, some gas or propane water heaters can continue operating during a power outage, depending on the model.

Learn how to Create an Energy-Efficient Home with the help of this article.

Tankless, or on-demand water heaters don’t store hot water. Instead, it uses a series of coils to heat water as it passes through. When comparing a tankless water heater versus a tank, there is one important difference: A tankless unit heats water when you need it instead of continuously maintaining a tank of heated water. A tankless heater can be more energy-efficient than a traditional storage tank water heater because the unit only heats water as you use it and it doesn’t have to keep unused water hot. A tankless water heater heats water on demand but can only supply a certain amount of hot water at one time. Check the unit’s maximum flow rate to make sure it can handle your household’s simultaneous hot water needs, such as running a shower and dishwasher at the same time.

Space is another factor when considering tankless versus tank water heaters. Tankless models have a compact design that can free up floor space. Because they don’t store dozens of gallons of water, there’s no storage tank that can rupture and release its contents. However, the unit and its plumbing connections can still leak. They typically have a higher upfront cost, however, and some households may need additional capacity to meet high hot water demand.

The right choice in a tank versus tankless water heater comparison depends on your household size, hot water use, installation space and budget.

Electric tankless water heaters provide hot water on demand without taking up as much space as conventional storage tank models. Electric tankless water heaters can have longer life spans than standard electric water heaters, but actual service life varies by model, water quality, usage and maintenance. While the initial cost may be higher, energy savings over time can help offset some of that expense.

If your home currently uses natural gas, replacing your old gas water heater with a natural gas tankless water heater might be a great choice for comfort and value. You can install these compact units inside or outside of your home. When comparing a gas water heater versus electric water heater, gas tankless units generally require proper gas supply and venting, while electric units require sufficient electrical capacity. Also, consider installation requirements, flow rate, household demand and ongoing energy costs when installing an electric versus gas tankless water heater. Have a qualified professional complete gas water heater installation.

Like natural gas models, liquid propane tankless water heaters can provide a compact hot-water solution. How much hot water a unit can provide at one time depends on its gallons-per-minute (GPM) rating, incoming water temperature, required temperature rise and fixture flow rates. When deciding between a tankless water heater versus a tank water heater, consider your household’s hot water demand and choose a unit that can meet it. Have a qualified professional complete the installation.

Check out our Tankless Water Heater Buying Guide for tips on how to find the right tankless hot water heater.

Mobile homes require a specific kind of water heater which must be approved by Housing and Urban Development (HUD). You can purchase both gas and electric water heaters for mobile homes, but if you select gas, be sure to buy the correct type — propane or natural gas — for your connection.

If these units are enclosed with no outside access, you’ll need to select a sealed combustion gas water heater. When you have outside access, standard gas water heaters are typically sufficient. Make sure to check your measurements carefully before installation as door openings in mobile homes have smaller-than-average sizing.

Water Heaters With Advanced Technology and Features

Some water heater models available now have advanced features and technology that make them perform better and work more efficiently.

Dry-Fire Protection

Available for electric water heaters, this feature keeps the upper element from burning out if the unit senses no water around it.

ENERGY STAR® Certification and High-Efficiency Ratings

ENERGY STAR^® certified water heaters meet government-backed energy-efficiency standards that can help reduce energy use and operating costs. Manufacturers also use a Uniform Energy Factor (UEF) rating to indicate efficiency — the higher the UEF, the more efficient the water heater.

When comparing high-efficiency water heater models, check the EnergyGuide label for estimated annual energy use and operating costs. More efficient models may cost more upfront but can provide energy savings over time.

Electronic Gas Valve

Some gas water heaters feature an electronic gas control valve that regulates gas flow and helps control water temperature. On certain models, a thermopile uses heat from the pilot flame to generate electricity for the control, so it doesn’t require an external power source. Some electronic gas valves also have an LED status indicator that displays operating information and diagnostic codes to help identify potential problems.

Wi-Fi Water Heater Capabilities

A Wi-Fi module is now available in select electric water heaters that lets you control your water temperature remotely. Depending on the model, scheduling and operating controls may help reduce energy use by limiting heating during periods of low demand. These units also send an alert if your tank is low on hot water.

Water Heater Accessories

There are many hot water tank accessories available to improve the safety and efficiency of your water heater.

Expansion Tanks

An expansion tank provides space for water to expand as it heats, helping control pressure in a closed plumbing system. Whether one is required depends on the plumbing system, manufacturer instructions and local code.

Water Heater Timers

A hot water heater timer lets you schedule when an electric water heater turns on and off. By limiting operation during times when you typically don’t need hot water, a timer may help reduce energy use and operating costs.

Water Leak Detectors and Alarms

Water leak detectors sit either on the floor or in the pan beside the water heater. They sense any leakage or overflow and emit an audible alarm to alert the homeowner to a problem. Some of these alarms are compatible with Wi-Fi and able to send alerts to a smartphone.

Water Heater Insulation Blankets

These blankets are made to fit over the unit and improves the insulating ability of the water heater. Insulating blankets are best for heaters that reside in garages or other unheated spaces.

Water Heater Pans

Water heater pans sit under the unit and help protect against water damage from leaks or condensation. The pan typically has an opening for a drain line that directs collected water to an appropriate drain. Follow the water heater manufacturer’s instructions and local codes for proper installation.

Water Heater Stands

Water heater stands raise a water heater off the floor when required for installation. Requirements vary based on the water heater, installation location and local codes. Adding a stand also changes the unit’s installed height, which can affect plumbing and venting connections. Follow the manufacturer’s installation instructions and applicable codes and hire a qualified professional when necessary.

Good to Know

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Find the Right Water Heater for Your Home

Choosing a water heater doesn’t have to be complicated. Start with your household’s hot water needs, then consider your available fuel source, installation space, energy efficiency and budget. When you take the time to compare your options, you’ll choose the water heater that works best for your home, family and everyday routine.

Ready to get started? Shop water heaters online or visit your local Lowe’s to explore your options.

Need help choosing the right water heater? Use our Water Heater Finder. Get started.

Hot Water Heater FAQs

Maintaining your water heater ensures optimal energy efficiency and gives you a chance to visually inspect components, helping you get a handle on small issues before they become big problems. Here are some basic tasks required to maintain your hot water heater. Always follow the water heater manufacturer’s maintenance recommendations.

Once or twice a year, visually inspect the water heater, looking for loose screws and connections and obvious signs of damage or leaks.
Flush the tank periodically to remove sediment and mineral buildup. Follow the manufacturer’s maintenance instructions for your model. Annual flushing is common, but hard water or heavy sediment buildup may require more frequent maintenance.
Ensure your temperature and pressure (T&P) valve is working properly.
Inspect the sacrificial anode rod and replace it if it deteriorates.

To keep your water heater operating smoothly, get the information you need on How to Maintain a Water Heater.

If you’re not a DIYer and need some help with performing regular water heater maintenance, contact a professional.

Manufacturers size storage tank water heaters by the amount of water they hold in gallons. As a general guideline, a four-person household might start by considering a 50-gallon tank. However, household size is only one factor. Your hot water habits and how much you use during peak periods also affect the capacity you need.

Also consider the water heater’s recovery rate, or how quickly it heats replacement water. The model’s First Hour Rating (FHR) estimates how much hot water it can supply during an hour of peak use, starting with a fully heated tank. Because FHR accounts for both tank capacity and recovery performance, look for a rating that meets or exceeds your household’s peak-hour hot water demand.

Yes; however, switching to a tankless water heater may require more than just replacing one unit with another. It requires significant infrastructure and utility upgrades. Depending on the model, you may need upgrades to your gas line, electrical system or venting as well as changes to plumbing connections. You’ll also need to choose a tankless unit with a flow rate that can handle your household’s simultaneous hot water needs. Before making the switch, check the unit’s installation requirements and have a qualified professional determine whether your home can support it.

The amount of space needed depends on the unit’s size, fuel type and manufacturer requirements. You need to account for the tank itself, allow the required clearances around the unit and enough room for connections, ventilation and future maintenance. Gas models may have additional ventilation and clearance requirements for safe operation, so ensure you always follow the manufacturer’s installation instructions and applicable local codes.

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How to Choose a Water Heater: A Buying Guide

Key Takeaways