When it comes time to replace your aging water heater, one of the first questions you may ask yourself is "What size water heater do I need and what else should I consider?" Getting the right size is important to ensure you have enough hot water for your household needs without overpaying. This guide will walk you through how to determine the appropriate water heater size for your home as well as a few other things to consider when looking into water heaters.

Check Your Hot Water Usage

The first step is estimating your home's peak hot water usage, also known as the first-hour rating. A first-hour rating indicates how much hot water in gallons the unit can supply per hour. You'll also want to take into account the number of bathrooms and bedrooms, the number of occupants, and everyone's daily schedule. Generally, we've seen that households estimate around 20 gallons per full bath, 15 gallons for a powder room, and 10 to 15 gallons per person.

Consider Sizing Up

It's better to get a water heater that's slightly too big rather than too small. A properly sized unit should be able to heat water continuously during peak demand periods. An undersized water heater will run out of hot water too quickly. In turn, you're left without the hot water you need. However, while you should size up a bit if you're in doubt, you want to avoid sizing up too much. Getting a tank that is too large can wind up using more electricity or gas, and in turn, cost you more. This is because you're constantly paying to heat a tank full of water that isn't being used. As such, selecting the ideal size for your unit is extremely important. It's best to talk with a water heating company to help determine what size will fit your household and needs.

Decide on Number of Water Heaters

For very large homes with multiple bathrooms, installing two smaller water heaters may make more sense than one oversized unit. This may also allow you to have smaller units in separate locations to serve different zones of your home. Installing water heaters in parallel allows both units to share the hot water load. The units don't require identical specifications, so you can mix and match sizes and fuel types if needed.

Consider Different Types of Water Heaters

While considering what size water heater will work best for you and your home, you'll also want to consider the two main types of water heaters: storage and tankless. Storage water heaters heat and store hot water in an insulated tank, available anytime you need it. Tankless water heaters heat water directly on demand, so there is no storage tank. Storage units, or tank water heaters, are less expensive upfront and easier to install, while tankless models save space and can lower energy bills. Tankless may make more sense for low-use households or secondary locations like pool houses.

Take a Look at Tank vs Tankless Water Heater Sizes

When it comes to a tank or storage water heater, the tank capacity is important to note. This refers to the interior volume of the storage tank, usually from 20 to 80 gallons, according to CNET. Go with a larger tank if you have high demand, but bear in mind it comes at a higher purchase price.

Tankless water heaters require a different approach since there is no storage capacity. Sizing is all about the maximum flow rate, measured in gallons per minute (GPM). We've seen that small units provide up to 2 GPM, medium units up to 3 GPM, and large units up to 5 GPM or higher.

You'll also want to pay attention to the minimum flow rate, the smallest amount of hot water the unit can heat at one time. The maximum and minimum flow rates together determine the useful range.

Consider Gas vs Electric Tankless Units

When considering the size and type of heater, you also need to decide between gas or electric power. Gas water heaters heat water faster with lower operating costs, while electric units don't need venting and are simpler to install.

As with storage models, tankless water heaters come in gas-powered or electric variations. Gas tankless provides very high flow rates for larger homes but is more complex to install. Electric tankless units require more power to achieve the same hot water capacities.

Look Into Different Brands of Water Heaters

Selecting reliable water heater brands with good warranties ensures your new system will last. Look for reputable manufacturers to help ensure you find a unit that lasts and is reliable. Check consumer reviews on sites like Consumer Reports to compare brand reliability. A plumbing service or hot water installation service can help advise you on what brands may be best for you. According to WebFX, the consumer plumbing market grew annually by 3.2% from 2017 to 2022. Also, make sure replacement parts are readily available, so your unit can be easily serviced if repairs are needed down the road. You can talk to a water heater installation company as well for any recommendations they have.

Get Help With Installation

Always hire professional plumbers to install a new water heater unless you are highly experienced in doing home plumbing repairs. Your installer can help select the right replacement unit and provide other hot water solutions if needed. They will also file permits, safely remove your old unit, and ensure your new system is properly vented and up to local codes. Also, hiring a professional is important if you're considering going tankless. Many homeowners don't have sufficient electrical capacity or gas lines. A qualified pro can assess your infrastructure needs and weigh the pros and cons of storage versus tankless for your home. They can also install multiple units if your household requires several smaller water heaters.

Figure Out the Cost of a New Water Heater

A new water heater can often range in pricing anywhere from $900 to $3,000, including professional installation, according to Forbes. This depends on the efficiency, installation process, and other common factors. You can sometimes offset some of these costs with rebates, tax credits, and incentives. Over the lifespan of a new unit, you'll also save substantially on utility bills, so an efficient water heater pays for itself over time.

Keep up With Water Heater Maintenance

With proper maintenance, a high-quality water heater should last 8 to 12 years, according to Bob Vila. Follow your owner's manual for draining and flushing the tank annually to control sediment buildup. Replace the anode rod every few years to prevent corrosion. Also, keep the exterior cleaned and the area around the unit clutter-free. If you experience any issues with your water heater, have it inspected and repaired promptly.

By correctly sizing your new water heater and buying from a leading brand, you'll enjoy plentiful hot water for years to come. Work with professional plumbers to ensure your new system meets your household needs. Over time, the energy savings alone often offset much of the purchase and installation costs. If you're looking to install a new one, we can help you select the right size. Call us at Martel Plumbing & Heating now to get started.