Plumbing, Water Heaters

Are Marathon Water Heaters Worth It? (Explained)

marathon water heater lg

Many consider Rheem a middle-of-the-road water heater manufacturer, but they have one ace in their pocket – the Marathon water heater range. These units are among the best electric tank water heaters available, but are Marathon eater heaters worth it?

Marathon water heaters are worth the money. These units are some of the best available. The long lifespan, lifetime warranty, and energy-saving features of the Marathon units will save money in the end. Few electric water heaters can compare with the unique Marathon range.

Marathon water heaters are unlike any others of their kind. Let’s take a closer look at the innovative features of these water heaters that make them stand out from the rest.

Is Marathon a Good Water Heater?

The Marathon water heater by Rheem is one of the best-selling high-end water heaters on the market, with good reviews from many customers, but is the Marathon a good water heater?

The Marathon water heater is one of the best models available from any brand or manufacturer. The Marathon stands out as a good water heater due to its many unique features, such as a lifetime warranty and corrosion-resistant tank. Few water heaters can compete with the Marathon.

Water heaters are essential for every modern home, and without a good model, there are many risks and challenges involved in owning a water heater. 

Low-quality water heaters are prone to damage, corrosion, rust, leaks, and even ruptures. For these reasons, every homeowner must equip their home with a high-quality, reliable water heater.

Few water heaters can match the Rheem Marathon in quality and reliability. Rheem is so confident in the Marathon’s performance that this heater comes with a lifetime warranty. No other water heater on the market can boast the same warranty.

The Rheem Marathon water heater is one of the best electric water heaters available. It is a prime example of a good water heater. 

There are three ranges of Marathon water heaters, including small point of use water heaters as small as 15 gallons, standard residential water heaters ranging from 30 to 100 gallons, and thermal storage tanks ranging from 50 to 105-gallon capacities.

The variety of Marathon models means there is a Marathon water heater available for every home and residential water heating requirement.

If you are in the market for a good water heater, look no further than the Rheem Marathon series. 

How Long Do Marathon Water Heaters Last?

Most conventional residential water heaters have a lifespan of about 8 to 12 years. Water heaters tend to be expensive, so every homeowner is looking for the longest-lasting water heater. How long do Marathon water heaters last?

According to Rheem, Marathon water heaters are designed to last for as long as a person would own a home. This seems like a big statement, but Rheem confirms their confidence by including a lifetime warranty on Marathon models. Realistically, Marathon water heaters can last upwards of 40 years.

The innovative design of Marathon water heaters allows these models to last for many years longer than most other available water heaters.

Marathon water heaters can last longer, even than tankless water heaters, known for lasting far longer than tank water heaters.

The incredible lifespan of Marathon water heaters is due to the two main features of these models. Marathon water heaters do not have an anode rod, and they are made from modern materials that are resistant to corrosion and the solvent properties of tap water.

Most electric water heaters have an anode rod made from aluminum or magnesium, which prevents the water from reacting with the heater’s inner tank, preventing rust within the tank. These rods have a limited lifespan, which is why most electric water heaters have a short life.

The lack of an anode rod immediately lengthens the lifespan of Marathon tanks significantly. 

Marathon water heaters have an inner tank made from seamless polybutylene, which is highly unlikely to be corroded or dissolved by tap water and will not ever rust. 

These features allow the Marathon an unusually long lifespan for an electric water heater.

How Much Do Marathon Water Heaters Cost?

One of the most important factors when considering a water heater is the initial cost outlay. A water heater is only worthwhile if the price of the heater is worth paying. How much do Marathon water heaters cost?

Marathon water heaters are some of the most expensive electric water heaters available. The initial cost outlay of Marathon water heaters is higher than most, but the features of these heaters do warrant the cost. Marathon water heaters cost an average of $835 – $1995, depending on the model.

There is a relatively large range of MArathon water heaters available from Rheem. The type of Marathon heater you choose and the fee your local supplier or retailer adds to the purchase price determine how much the water heater will cost.

The average price for the smallest, on-demand Marathon water heater is typical $835. This will buy a 15-gallon water heater with a 2000W heating element. These heaters are small but perfect for a single-person apartment or other small dwellings or buildings.

The largest residential Marathon water heaters may cost as much as $1995, but this heater is much larger with a 105-gallon capacity and a 3800W heating element. These models are ideal for larger households and higher volume requirements. 

Ultimately, the Marathon water heater range is expensive compared to other electric water heaters, but the features and lifespan of these models are unparalleled. 

Do the features and lifespan of the Marathon water heater range warrant the high prices? Let’s examine how worthwhile these heaters really are.

Are Marathon Water Heaters Worth the Money?

Marathon water heaters cost a lot to purchase, but is the high price worth it? Are Marathon water heaters worth the money?

Marathon water heaters are worth the money. These heaters are superior to almost all other electric water heaters on the market. The following are some of the qualities that make them stand out from the rest of their competitors:

  • Longer lifespan
    The long lifespan of Marathon water heater tanks means that the appliance will likely not require a replacement during the time that one person owns the house.

    This alone will cover the cost of the Marathon water heater, as other models will require a replacement in as few as 8 years after installation, while the Marathon models will last for more than 40 years in some instances.
  • Efficiency
    The high initial cost of Marathon water heaters can seem daunting, but the high price is warranted. These heaters cost more, but they are far more efficient than other self-cleaning water heaters.

    If a water heater is not efficient, it costs more money to run. A water heater is responsible for up to 20% of the overall cost of most households. Having an efficient water heater that is cheaper to run and maintain will save the owner significant amounts of money over time.
  • Environmentally friendly
    Rheem Marathon water heaters are designed to be as efficient and energy-saving as possible while being constructed from environmentally friendly materials.

    Marathon electric water heaters do not use an anode rod to prevent internal damage and corrosion. Instead, they are made from a corrosion and solvent resistant material called polybutylene. 
  • Low maintenance
    These water heaters require far less maintenance than other types and brands of water heaters, which results in further savings for the owner. 

For these reasons, the Marathon water heater is definitely worth the money.

Marathon Water Heater Pros and Cons

Marathon water heaters are among the best on the market, but these models are not without flaws. Let’s examine some of the pros and cons of Marathon water heaters.

Marathon water heaters have a lifetime tank warrantyMarathon water heaters are only available as electric models. No gas or tankless models are available
Marathon water heaters last significantly longer than other modelsMarathon water heaters are not as widely available as other brands
Marathon water heaters are far more efficient than other modelsMarathon water heaters are not available in as large capacities as some other models
Marathon water heaters are very environmentally friendlyMarathon water heaters are costly
Marathon water heaters are lighter than most other water heaters
Marathon water heaters are much more robust and tough than other models
Marathon water heaters are corrosion and solvent-resistant
Marathon Water heaters can withstand higher pressures for longer periods
Marathon Water heaters have superior insulation than most other models
Marathon water heaters are easy to install
Marathon water heaters require little maintenance

What Makes the Marathon Water Heater Stand Out?

Marathon water heaters are some of the best electric water heaters available internationally. Rheem has worked hard to produce the best, most efficient, and most reliable water heater possible.

However, every manufacturer applies the same effort to their water heaters, so what makes the Rheem Marathon range stand out from other models and brands?

Marathon water heaters feature many attributes that other models do not. Marathon has superior insulation technology, a lifetime warranty, a polybutylene inner tank, and a filament-wound fiberglass outer tank with a tough outer shell. These heaters can withstand intense pressure and are very energy efficient.

Most water heaters are made in the same way. The tank is filled with cold water by a dip tube. The water is heated with an element within the tank or a burner below the tank. A disposable anode rod is used to help prevent internal rust, corrosion, and solvents. Insulation is usually relatively minimal, which detracts from efficiency, and most water heaters are made from environmentally damaging materials.

But, Marathon water heaters are different. Marathon electric water heaters are made of polybutylene, which is corrosion-resistant but does not damage the environment.

Typical water heaters only last for 8 – 12 years due to the deterioration of the anode rod. This allows the Marathon a significantly longer lifespan than other water heaters and requires far less maintenance than other electric tank water heaters.

The insulation materials used in Marathon models are a proprietary material made by Rheem known as Envirofoam. This material is an incredible insulator, and all Marathon units are equipped with 4 inches of it between the outer tank and the shell. 

This results in even the largest Marathon tanks losing less than 5 degrees Fahrenheit of heat through the tank’s walls. This attribute makes Marathon heaters significantly more energy-efficient than other models, making them much less expensive to run and maintain.

This Envirofoam is made from environmentally friendly materials and uses no ozone-depleting chemicals. 

The heating elements within Marathon tanks are much more efficient than those in other electric tank heaters, and the construction of Marathon tanks can withstand more pressure than other tanks.

All of these features are useful, but the most stand-out feature of Marathon units is the lifetime warranty provided by Rheem. No other water heater offers such a warranty!

This no-leak promise demonstrated Rheem’s confidence in their product, and the user reviews of Marathon units confirm that this warranty is well-founded.


At the end of it, few electric tank water heaters can compete with the Rheem Marathon range. These are the best units around in almost every area.

However, the price of these units and the fact that they are not the biggest nor the most readily available units on the market are drawbacks.

The Marathon units are a worthwhile investment, but only if you have the budget available. If you can afford it, these water heaters a well worth it.

Sources: – Marathon Water Heater


Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.