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How Much Does a Water Heater Weigh? – Average Weight Facts

Fact checked by Stephen Conklin

how much does a water heater weigh

Are you looking to replace your water heater or install one for the first time? Are you wondering “how much does a water heater weigh?” Learning a water heater’s weight will give you an idea of whether to complete the installation yourself or enlist a professional plumber to do it for you.

Some water heaters are lightweight, while others might require a three-person crew to have them set up. I prepared this article to give you a glimpse of how much water heaters weigh, including the factors impacting this attribute.

Table of Contents

What Is the Average Weight of Water Heaters with Different Storage Tank Capacities?


Water heaters with storage tanks are heavier than tankless systems, even when empty. It would be wise to understand that most storage tank water heaters come with a metal container, either galvanized steel or stainless steel. Some brands might even have cast iron hot water tanks.

Unfortunately, there are no definite answers to the question, how heavy is a water heater with a storage tank? Manufacturers use different materials and integrate various technologies that can add to or reduce their water heater’s weight. The best we can do is to get the average of several systems.

The average weight of a 40-gallon water heater is 440.5 pounds when full and only 110 pounds when empty.

Here is a rundown of some market-leading 40-gallon water heaters and their respective weights.

  • Rheem Marathon MR40245 – 425 pounds (empty weight = 91 pounds)
  • Rheem XE40M06ST45U1 – 440 pounds (empty weight = 106 pounds)
  • Sure Comfort SCG40T03ST34U1 – 459 pounds (empty weight = 125 pounds)
  • Westinghouse WER040C2X055N – 438 pounds (empty weight = 104 pounds)

Of the above heaters, the lightest one is the Rheem Marathon MR40245 with an empty weight of 91 pounds. The heaviest is the Sure Comfort SCG40T03ST34U1 at 125 pounds.

How about an 80-gallon water heater? It would be safe to assume it is heavier than a 40-gallon unit. However, it would be inaccurate to say an 80-gallon appliance weighs twice that of a 40-gallon device. On average, an 80-gallon water heater is about 200 pounds.

Let us look at some of the more popular 80-gallon water heater options.

  • A.O. Smith Signature Premier – 969 pounds (empty weight = 302 pounds)
  • Rheem GHE80SS-130A – 1,267 pounds (empty weight = 600 pounds)
  • Richmond S80U-1 – 859 pounds (empty weight = 192 pounds)
  • Westinghouse WEC080C2X045 – 818 pounds (empty weight = 151 pounds)

The Rheem GHE80SS-130A is the heaviest among the above 80-gallon water heaters. Its water heater weight empty is nearly 1.5 times heavier than the Rheem 40-gallon Marathon MR40245’s full weight.

Read more: How much does a 50-gallon water heater weigh?

What Is the Average Weight of Tankless Water Heaters?

The average tankless water heater weight is 27 pounds. Below are some popular tankless models and their weights:

  • 2.54 GPM Rheem RETEX-13 = 7 pounds
  • 3.51 GPM EccoSmart ECO 18 = 11 pounds
  • 4 GPM EccoTemp i12-NG = 29 pounds
  • 4 GPM Titan Model N-120 = 8 pounds
  • 5.4 GPM Black+Decker BD-27HD = 12.17 pounds
  • 6.5 GPM Rinnai V65iN = 45.6 pounds
  • 9.5 GPM Rheem ECOH200DVLN-2 = 82 pounds
  • 9.8 GPM Rinnai RL94iN = 46.3 pounds
  • 11 GPM Rheem ECOH200DVRHLP = 85 pounds

What Factors Affect a Water Heater’s Weight?


You might have noticed from the examples above that water heaters have different weights. Products might have the same hot water capacity or are under one brand, yet they still weigh differently. Here are several factors that can impact water heater weight.

Water Heater Type

Undoubtedly, storage tank water heaters are heavier than their tankless counterparts. The reason is obvious. The storage tank can add at least 80 pounds to the water heating device, depending on its capacity.

In general (though this is not always the case), the greater the storage tank capacity, the heavier the water heater. Filling the tank with water also increases its overall weight.

On the other hand, on-demand water heaters do not use tanks to store water. These appliances heat the water as it passes through the heat exchanger coils inside the water heater, eliminating the need for a storage tank.

Water Flow Rate

Tankless water heaters are lighter, and you should consider their water flow rate (GPM) to determine whether they are lightweight or heavy. As a general rule, the higher the water heater’s flow rate, the heftier it is.

For example, a 5-GPM water heater might weigh 10 pounds, while a 10-GPM appliance can tip the scale at 30 pounds.

Water Weight

It would be wise to remember that a gallon of water weighs 8.33 pounds at room temperature. Of course, nobody would want to shower with room-temperature water.

Heating the water decreases its weight because increased temperature agitates the water molecules, reducing the overall density. Hence, heating the water to 200 degrees Fahrenheit will reduce its weight to 8.04 pounds per gallon.

The water’s weight explains the weight differential in tankless water heaters. We said that tankless water heaters with a higher GPM rating are heavier than units with a lower GPM.

For example, suppose you have a 5-GPM water heater. In that case, it can weigh up to 40 pounds during operation (5 gallons x 8.04 to 8.33 pounds). On the other hand, a 3-GPM tankless water heater will only weigh about 24 pounds (3 gallons x 8 pounds).

Material Construction

The materials used in the water heater’s manufacture can also contribute to its weight. For example, a stainless steel electric water heater weight is greater than galvanized steel but lesser than cast iron water heaters.

Some companies also use high-density polyethylene polymers, fiberglass, and other water heater tank material technologies.

In addition, tankless water heaters with a higher GPM rating often have more heat exchanger coils or larger-diameter tubes than low-GPM units. These design attributes can increase weight.


Answering the question “how much does a water heater weigh?” depends on the water heater type, storage tank capacity, and water flow rate.

  • Water heaters with storage tanks can weigh 20 pounds to 600 pounds or more, depending on the storage tank capacity.
  • Tankless water heaters can weigh between 7 pounds and 85 pounds, depending on the water flow rate.

Ideally, people should never handle any object that weighs more than 55 pounds for men and 35 pounds for women. It would be wise to hire professionals or ask for assistance if your water heater is heavier than these safe weight limits.

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