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Water Heater Weight Tables (Empty+full for all sizes)

When looking into a water heater for your home and preparing yourself for installation, knowing the heater’s full and empty weights is very useful. You can then make sure that you have enough help to install it and that the floor (or ceiling) can support it.

A variety of factors influence how heavy a water heater is, including the lining of the interior, energy usage type, and how large the heater is (the capacity). Although it may seem like bigger is better, this is not necessarily the case with water heaters.

The average domestic water heater is 40-50 gallons.
  • Gas models weigh 157-178 lbs empty and 491-595 lbs full.
  • Electric models weigh 114-141 lbs empty and 448-558 lbs full.
  • Stainless steel models weigh 129-150 lbs empty and 463-567 lbs full.
  • Hybrid models weigh 203-213 lbs empty and 537-630 lbs full.

Water Heater Sizing

There is a great range in the size of water heaters because they need to supply hot water to all sorts of sizes of homes. 

Water heater installed in a white wall with windows

At the smaller end, it seems that the lowest volume for a tank-style water heater is about 20 gallons. Of all the brands I explored, the lightest 20-gallon tank I could find was about 60 pounds. 

At the larger end, the largest volume for a tank-style water heater I could find was about 100 gallons. One of the 100-gallon water heaters was upwards of 356 pounds, making it more than five times the weight of the smallest tank-style water heater that I found! 

It seems that it is most common to have the water heater size change in increments of 10 gallons, with increments of 5 gallons used a bit less often. 

Despite this, some tank sizes are listed at 28 or 29 gallons rather than 30 gallons, for example. These slight differences in volume are negligible, though, and don’t have a significant impact on the weight either.

More precise volume measurements are integral to upholding a brand’s integrity, but overall, a 28-gallon and a 30-gallon water heater will operate very similarly and with similar efficiency.

For the average household, 40- or 50-gallon tanks are common. 

What Impacts The Weight of a Water Heater

Heating Mechanism

Whether your water heater is electric, gas, or a hybrid (heat pump), the different components of how they heat water will impact how heavy the entire water heater is. 

Although gas and electric water heaters of the same tank volume appear to be similar in size, they have different technology that heats the water. 

Gas water heaters are often bulkier than electric water heaters because their heating mechanism produces exhaust, which must be vented outdoors. The extra ventilation components are what add weight to gas water heaters. 

A 50-gallon electric water heater’s weight may range from 100-150 pounds, but a 50-gallon gas water heater’s weight can range from 160-250 pounds. 

50 gallon electric water heater weight versus 50 gallon gas water heater weight

Not only are there differences in weight between a gas and an electric water heater, but hybrid water heaters often weigh more.

To understand why hybrid water heaters often weigh more than other kinds of water heaters, we must first understand how hybrid water heaters work

Hybrid water heaters do not heat the water directly, but rather, they absorb heat from the surrounding air, convert it to heated gas, and use this gas (enclosed in coils) to heat the water via conduction. 

To do this, they utilize heat pumps which require a fan, condenser, and evaporator that other types of water heaters do not use. These devices add to the size of a hybrid water heater, making them weigh more than most other water heaters. 

50-gallon hybrid water heaters can range from 200-300 pounds, while the electric and gas water heaters’ weights range only from 100 to 250 pounds.

Tank vs Tankless

Although the heating appliance and other mechanical devices that allow the water heater to do its job contribute to its weight, the tank of a water heater is what accounts for lots of the weight of the product. This is because a tank must be large and robust enough to hold up to 100 gallons of water. 

That being said, the water heater becomes much lighter when the large storage tank is eliminated from the equation.

A tankless water heater can be as light as 15 pounds and only gets to about 100 pounds.

Rheem 11kW 240V Tankless Electric Water Heater

But how does a tankless water heater work without lots of storage?

Instead of keeping a large supply of heated water, tankless water heaters heat water as it is needed. Because only enough water to supply the demand is heated, lots of energy savings can be experienced. 

Tank Style

Tanks can influence the weight of the water heater in more ways than one. The style of the tank, or whether it is glass-lined vs. stainless steel lined, can impact the weight of the entire water heater. 

Glass-lined tanks do not only consist of glass; the majority of the tank is made of steel. The glass is instead a layer on top of the steel interior.

Because the glass lining is an addition rather than a substitution, a tank that is glass-lined will be heavier than its stainless steel counterpart (when the same size of tank is being compared). 

In other words, a glass-lined tank is basically a stainless steel tank with an added glass layer, which contributes to a higher weight.

The function of a glass-lined water heater tank is to shield the sensitive steel (not stainless steel for these water heaters) from corrosive materials in the water. Stainless steel is less corrosive, so it does not need this added protection.

Tank Size

With water heater tank sizes ranging from 30 to 100 gallons typically, the differences in volume can dramatically change the weight of the water heater. 

As mentioned before, the larger the capacity of the water heater, the heavier it will be since the tank will have to be larger to fit more water.

Although we have only mentioned empty weight before (the weight of the water heater without water), water can also add a lot of weight to a water heater as more and more gallons are stored. 

Water Heater Weight Tables

The tables below have data pulled from several different brands, models, sizes, and types of water heaters. 

I gathered as much data as I could for each size and averaged it out to find the empty weight of the water heater. 

For the full weight, I added the weight of the water to the empty weight. 

Glass-Lined Water Heaters

Gas Water Heaters

Size (gal)Empty Weight (lbs)Full Weight (lbs)

Electric Water Heaters

Size (gal)Empty Weight (lbs)Full Weight (lbs)

Stainless Steel Water Heaters

Few water heaters do not have glass lining or some other kind of protection inside of their tank, so I was not able to find sufficient data for each size and different types of water heaters (electric vs. gas). 

Because of this, the data is compiled onto one, compact table. 

Size (gal)Empty Weight (lbs)Full Weight (lbs)

Heat Pump/Hybrid Water Heaters

Much like stainless steel water heaters, heat pump/hybrid water heaters are a bit more limited in their size range. 

This is most likely because they are a fairly new development and only the most popular tank sizes are being prioritized. 

Size (gal)Empty Weight (lbs)Full Weight (lbs)

Tankless Water Heater

Gallons Heated Per Minute (GPM)Weight (lbs)

Calculating Water Weight

Most of the full weight of a water heater comes from the water. To have a good idea of how much your water heater really weighs, you should calculate the full weight of a water heater.

If you know both the volume of the tank and the empty weight for your water heater, no matter the kind, you can calculate the approximate full weight fairly easily.

Just multiply the volume of the tank by 8.34, which is how many pounds a gallon of water weighs. 

Once you add the water’s weight and the empty weight, which can be found on the packaging, you have the full weight. 

Water heater weight + (Tank volume x 8.34) = Full water heater weight

Formula or equation for full water heater weight

Ideal Domestic Water Heater Size

Water heaters can certainly be quite heavy, but they also take up quite a bit of space in the home. 

This is commonly why they are stored in the basement of a home, but if your home doesn’t have a basement, this can make fitting a water heater much more difficult. 

In order to save space and money, it is wise to research what water heater size is the best for you so you don’t get one that won’t support your family or one that is far too large. 

Many water heater services will have a calculator on their website that will ask you about how long on average you shower, how large your bathtub is, if there is often back-to-back or simultaneous shower usage, and similar questions. 

The ideal shower uses about 17 gallons of water in 8 minutes on average.

If your shower runs, for example, for 30 minutes, at a rate of 2.5 gallons per minute, you would need a water heater that is 75 gallons or larger to supply hot water for this whole shower. 

After this maximum is used up, your shower will run cold as well as other appliances that use hot water. 

Instead of calculating all of the water usage used by appliances that need hot water, an estimate can be used. 

  • For households of 1 or 2 people, a 23- to 36-gallon water heater should suffice. 
  • For 2 to 4 people, a 36- to 46-gallon water heater should be enough. 
Water capacity of water heater per household number

The estimates go up in increments of 10 gallons from here. 

For the average family, a 40- or 50-gallon water heater should be enough.

Implications of Larger Heaters

Let’s say you live in a home with more than five people, run a B&B, or you just love long, hot showers and hate running out of hot water. In these cases, you will need a water heater larger than 50 gallons or more than one small water heater.

Although cost is definitely a factor, there are many other factors that can make large or multiple water heaters troublesome or even dangerous. 

Additional Weight on Ceilings

As tank sizes grow to 80 gallons and above, it is likely that they can get up to half a ton when they are full of water. 

This is another reason why putting your water heater in the basement is ideal. With a basement, you don’t have to worry about empty space beneath the water heater. Instead, there is solid ground beneath it to support this weight. 

Having a water heater in the ceiling instead of solid ground can be a safety concern since the ceiling can crack and even break with too much weight on it. A water heater falling through a ceiling can cause terrible damage to the heater as well as to objects and people below it. 

This can be prevented with adequate reinforcement and prioritizing the placement of the water heater in a basement or the ground floor if there is no basement. 

Ease of Installation

The heavier the object, the more difficult it will be to install it. This is especially true for water heaters because of their large size and weight. 

Although basements are ideal for space and the security of water heaters, getting a water heater down the stairs can be difficult. 

If you are more conservative with your water heater size, you can avoid installation pains (not to mention replacements, which involve carrying one unit upstairs and another one downstairs).

Energy Costs

As well as the outright cost of a larger water heater, the energy costs would also be terrible.

A larger volume of water in the tank means that more energy must be used to heat the water as it is being replaced and keep it warm. 

Woman adjusting the temperature of the water heater

Even if the water isn’t used constantly, the water in the tank must be kept warm at all times, and with a high volume, the costs will be high.

Water Heaters Bursting

Although having a storage of hot water can be nice when multiple people are bathing or showering, this excess of hot water can be especially damaging the more of it there is. 

When a water heater bursts from lack of maintenance or a malfunction, the more water there is, the more damage there will be. 

Imagine 75 to 100 gallons of water spilling into your home!

Not only will the water be at a high temperature that may be damaging to occupants and pets, but the floor, furniture, electronics, and other sensitive objects will be subject to water damage. 

This water will not be easy to remove, especially if the water heater is located in a basement. 

Even if the damage is only a leak and not an explosion, there is more water that can be leaked into your home.


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