7 Questions to Ask Before You Buy a New Water Heater

The cost of heating water consumes about 17% of our annual energy use, so when it’s time to replace your water heater, it’s worth doing some research to find the right one.

Choosing a new water can be confusing, with numerous brands and options to sort through. You need to find a water heater that will provide enough hot water yet be energy efficient and save you money. It’s best if you ask some questions before buying to narrow down your choices and pick a water heater that’ll serve your needs for years to come.

Here are seven questions to ask before you buy a new water heater:

1. What are some of the different types of water heaters on the market?

Three of the most popular water heaters are conventional storage water heaters, tankless water heaters, and solar water heaters.

Storage tank water heaters

You’re probably already familiar with storage tank water heaters, as they’re the most commonly installed type. They contain a storage tank where water is heated and stored for use. They come in both gas and electric versions and various storage capacities.

Tankless water heaters

Tankless water heaters heat water on demand without using a storage tank. You can use one for an entire home or hook it up to individual appliances. There are gas and electric versions, although gas tankless water heaters are the most energy-efficient.

Solar water heaters

Solar water heaters are popular in Arizona, thanks to our abundance of sunny weather. Solar panels heat water that then goes into a storage tank. These units generally need a backup system for cloudy days.

There are two types of backup systems, depending on whether you have a one or two-tank system. In a one-tank system, the backup water heater and solar storage are combined in one tank. In a two-tank system, the solar water heater preheats the water before transferring it to the conventional water heater.


2. What are the advantages and disadvantages of each type of water heater?

Storage tank water heaters

New storage tank water heaters are much more energy-efficient than in the past. The tanks are usually heavily insulated, and you can choose the brand, tank size, and fuel type that best meets your needs. Some models have lined tanks to prevent corrosion and technology that reduces sediment buildup.

Storage tank water heaters cost less and are less expensive to install than other types of water heaters. Your utility bills will be lower with a gas water heater than an electric one, but gas water heaters generally cost more to install than electric water heaters.

Tankless water heaters

Tankless water heaters provide hot water only as you need it, so they’re more energy-efficient than storage tank water heaters. However, the water flow per minute tends to be less with tankless heaters, so they may not be the best choice if you need hot water for multiple uses at once.

Tankless water heaters cost more to purchase than storage tank models, but they have a longer life expectancy and cost less to operate. They’re best suited to homes that use natural gas, as tankless electric models use a lot of power and may require an electrical upgrade to your home.

Solar water heaters

Solar water heaters use roof-mounted cells to absorb heat and transfer it to the water tank. They can save you a lot of money in the summer when Arizona’s energy costs are the highest. Federal and state rebates are available on solar heating units, offsetting some of the cost of installation. SRP and APS both have rebate programs, as well.

There are also a few disadvantages to solar water heaters. They need a backup system for cloudy days, and not every home may be able to accommodate the rooftop solar panels. Purchase and installation costs are also higher for solar systems than other types of water heaters, so it may not be the best choice if you think you may be moving in the next few years.

3. Should the fuel source be a consideration in which type of water heater we buy?

Yes, as there are pros and cons to each type of water heater depending on your fuel source. You may be considering a tankless water heater, for example, but if your home is all-electric it may not be the best choice.

One type of heater may use a fuel type more efficiently than another. You’ll need to carefully consider how each type of water heater will impact your energy costs before deciding which one is best for your home.

4. For a storage-tank water heater, how do we know what size to purchase?

All new conventional storage-tank water heaters have an EnergyGuide label attached to the tank. It lists the first-hour rating (FHR), indicating how much hot water you’ll get from the tank in the first hour of use, starting with a full tank. You use this rating to determine what size tank you’ll need.

First, figure out when your household uses the most hot water each day, such as in the morning when everyone’s getting ready. The energy.gov website has a calculator that estimates the amount of hot water consumed by various tasks.

For example, a shower uses approximately 10 gallons, running the dishwasher uses 6 gallons, a washing machine uses 7 gallons. So if you have three people taking showers while the dishwasher and washing machine are in use at your home, the FHR is 43. You would need a tank water heater with a first-hour rating near 43.

Make sure and buy the correct size water heater for the amount of hot water you need. If your household uses 100 gallons of hot water a day, it doesn’t mean you need a 100-gallon storage tank. Buying an oversized unit with more capacity than you’ll use will cost you more to purchase, and your energy bills will be higher.

5. What else should we consider about storage-tank water heaters before buying?

Storage-tank water heaters come in a variety of prices, sizes, and with various features.  The lowest-priced tank water heaters are not necessarily the best value, as they may cost more to operate and may not last as long.

Unlike on-demand tankless water heaters, storage-tank water heaters are always heating water, so they experience standby heat loss. There’s a thermal resistance rating for standby heat loss known as an R-value. Look for tank water heater models with an R-value of R-12 to R-25.

Also, be aware that a new tank water heater may not fit where your old one was, as new units are more heavily insulated than in the past and may be taller and broader than older units. If your new water heater must fit into a confined space, make sure you’ve checked the measurements.

6. Since tankless water heaters cost more to purchase and install than tank water heaters, are they worth the extra cost?

Tankless water heaters are anywhere from 8-34% more energy-efficient than storage-tank water heaters. You’ll save money in energy costs with a tankless water heater. If your home uses natural gas, a tankless water heater may be a worthwhile investment, especially since a tankless unit’s life expectancy is about 20 years.

As tankless water heaters don’t store water, you’ll need to check the gallons-per-minute rating (GPM) to determine if tankless is the right choice for your home. A higher GPM means the unit can deliver more water. A general hot water flow rate for tankless water heaters is 2-5 GPM. If you have a large household that commonly uses hot water for multiple purposes at once, you may need more than one tankless unit.

The purchase and installation costs are higher for tankless water heaters, but they last longer and cost less to run than storage-tank water heaters. A tankless model may well be worth the extra cost for your home.

7. Is it worth the expense to install a solar water heater?

In sunny Arizona, it can be well worth the investment. Summer energy costs tend to be high here, and you can definitely save money on your utility bills with a solar water heater. Over time, the savings can be thousands of dollars.

The main disadvantage of solar water heaters is the upfront expense, which is partially compensated for by federal, state, and utility company incentives. However, the solar panels can last for 20 years or more, and the sunshine is free.

If you plan to live in your home for the next few years, a solar water heater should be one of the options you consider before buying.

Next Steps

Donley A/C & Plumbing professionals offer first-rate, caring customer service and can repair or replace your water heater. The Donley team has an A+ BBB rating and has been recognized twice with their Ethics Award. Family-owned and operated, we’re proud to continue the legacy of outstanding, ethical service and giving back to the community. Call now for valley-wide service 7 days a week at 602-787-3956.