How Much Do Water Heaters Weigh?

Do you need to move a water heater? Then you're probably wondering: how much do water heaters weigh? There's no standard water heater weight, though they tend to range from between 40 pounds for a tankless version to 200 pounds for a large water heater. The capacity, type, and design of the water heater will all impact its weight. 

What Is the Standard Water Heater Weight?

There isn't a standard water heater weight for a few reasons. First, water heaters are available in a few different styles, notably tankless and tank heaters. A tank heater keeps a certain amount of water hot and ready to go. Since it needs to have enough space for all that water, it weighs considerably more than a more compact, tankless model. And, that's before it's full of water. 

While there's no standard weight for water heaters, there is a common range. For example, you can expect a tank water heater to weigh at least 100 pounds if empty. Meanwhile, tankless heaters often weigh in under 50 pounds.

Water Heater Weight by Type

Your mileage may vary based on the water heater's brand and overall design, but the bigger the heater, the heavier it is.

Tank Water Heater

A few factors affect the weight of a tank water heater, such as its capacity and the materials it's made from. A water heater with a stainless steel tank is likely to weigh less than a copper tank, for instance.

The size of the tank also impacts the weight, as the bigger the tank, the more materials are needed overall. 

One thing that doesn't change from one water heater to the next is the weight of the water itself. A gallon of water weighs 8.34 pounds. So if you fill up a 40-gallon tank, you'll add 333.6 pounds to the water heater's weight.

Tankless Water Heater

Tankless water heaters are much more compact than their tanked cousins, giving them a considerably smaller overall footprint. Some models are small enough to tuck in a cabinet beneath a sink. 

Since tankless models don't store water, you don't have to account for any additional water weight.

How to Measure the Right Size Water Heater

If it's time to replace your water heater, weight is just one consideration. What matters most is the heater's capacity. The bigger your household and the higher your hot water demands, the bigger your water heater needs to be. 

If you're considering the heater's weight because you're interested in installing a water heater yourself, remember that there's more to water heater installation than weight. You'll need to ensure the heater is installed correctly and that it aligns with local water heater installation codes. In most cases, your best bet is to hire a professional water heater installer near you rather than DIY.

Finding the Right Size Water Heater

Whether you go for a lighter-weight tankless water heater or a heavier tanked model, what matters most size-wise is how big your household is and how much hot water you'll need during peak usage times. Here's how to find the right size water heater.

Household Size

The smaller your household, the smaller your water heater can be, at least for tanked models. For example, if just one or two people live in your home, you can most likely get by with a 40-gallon model. If five or six people call your place home, then a bigger, 80-gallon model will likely be the best fit.

Number of Water-Using Devices

Whether your water heater is tanked or tankless, the number of hot water-using devices, particularly if those devices will be used simultaneously, plays a role in determining the right size.

Tanked water heaters use what's called "first-hour rating" to determine the appropriate size.

Let's say it's a Saturday morning. You want to run a load of clothing through the washer, and your two teenagers both need to take a shower. The washing machine uses about 25 gallons of hot water per load, and the shower uses 20. That means you'll need at least 65 gallons of hot water to get through a peak hour of usage, so look for a water heater with a first-hour rating of at least 65. 

Flow Rate and Temperature Rise

In addition to the number of water heating devices your household uses, tankless water heaters rely on flow rate, or the number of gallons per minute used by your shower, washing machine, and so on.

Temperature rise is another essential consideration when sizing a tankless water heater. It calculates how quickly your water heater can get the hot water to the desired temperature. Often, a temperature rise of 70 degrees Fahrenheit is ideal, to get cold water (50 degrees F) up to 120 degrees F.