Water Heater Elements: Are They Universal? A Practical Answer

The heating element is what actually makes the water hot inside your tank. Metal coils extend into the heater, and electricity running through them heats the surrounding water. Planning a replacement? Make sure you know what size socket you need for your water heater element before you start.

Cold water enters through a tube at the bottom of the tank, and the heating element brings it up to your desired temperature.

Every electric water heater has at least one element near the bottom of the tank. The default setting is usually around 120 degrees Fahrenheit. Larger models like the best 50-gallon electric water heaters typically run dual elements for faster recovery.

Are Water Heater Elements Universal?

The default temperature of a water heater is usually set to 120 Fahrenheit, but are water heater elements universal?

Varieties of Heating Elements

There are two major varieties of heating elements: screw-in and bolt-in.

Both have completely different electrical power ratings and may work on either 120 or 240 voltage.

Screw-In Elements

Screw-in elements are the most common type used in water heaters today. These are generally used on all newer water heaters, and the heating element is screwed into place.

Bolt-In Elements

Bolt-in elements are found primarily in older water heater models. There are several different styles available, and four bolts hold the heating element in place.

If you’ve an older tank that uses bolt-in elements, you’ve options. A universal adapter kit is available that allows you to convert from a bolt-in to a screw-in element, which is the more modern and easier-to-service option.

How Do Water Heaters Work?

When electricity passes through an element, it meets resistance. This resistance creates heat, similar to rubbing your two hands together very fast.

The wattage determines how much heat will be produced.

Electric water heaters operate using either one or two heating elements. These are managed by thermostats or a microchip control module that heats the water to the specified temperature.

A standard residential electric water heater consists of a manual reset high limit switch, upper thermostat, lower thermostat, one or two heating elements, and wires. When you turn on the power, the upper element energizes first and heats the water in the upper third of the tank.

Once the upper third reaches the temperature set by the upper thermostat, power switches to the lower element. The lower element then continues heating until the water temperature in the lower portion reaches the lower thermostat setting.

Impact of Water Hardness on Energy Consumption

Water heating appliances are among the highest electricity consumers in most households globally. Poor water quality can significantly affect the efficiency of these appliances. Adding hydrogen peroxide to your water heater can help combat hard water issues and protect your elements.

The water heater element was tested with and without electronic descaler technology. The results showed that the accelerated scaling technique developed for shortening the scaling time of the water heater element was successful.

Plus, the results have shown that scale formation of 1.5 KW and 3KW water heater elements due to total water hardness inflated the power consumption by 4% to 12%.

How Do I Determine Which Type of Water Heater Element I Need?

Finding the right replacement element requires some basic research. Here are the steps to follow.

First, examine your existing heating element to determine whether it’s a screw-in or bolt-in type. Next, you need to determine the voltage and wattage of your current element.

This information can be found on the label fixed to the side of your water heater tank. Compare and match your results to the specifications available for replacement elements.

Select the voltage that matches your setup, either 120 or 240. Then select the wattage that’s closest to your current electrical power rating.

Make sure the tank diameter of your water heater can accommodate the heating element you’ve chosen. Also consider your water quality, as ripple style or fold back style elements are especially helpful for those with hard water.

These specialty elements function the same way and have the same voltage and wattage, but their greater surface area causes less wear on the element over time.

How to Choose the Right Water Heater Heating Element

When choosing the right replacement element, you need to consider three critical factors: element flange style, wattage and voltage, and watt density.

Element Flange Style

Water heater parts have been sold in different styles throughout the years. Manufacturers have used various methods of installing elements into their water heaters since the innovation of the modern water heater.

The most common types are the Round Head style, Flat Flange, and the Universal Flange. The Flat and Universal flange elements are fixed to the tank using four 3/8” bolts.

The Round Head element is bolted to the tank using a separate four-bolt flange. Today, all residential water heater manufacturers only use screw-in style elements.

This style allows for easy serviceability and installation since it bolts into a spud welded directly on the tank. The thread is standard for all residential water heaters that use screw-in elements.

Important Things to Keep in Mind

You need to understand the voltage and wattage requirements of your specific unit. There are also screws, flange, and raised flanged type designs to consider.

You can find the voltage and power information from the water heater label or on the old element itself. A flange type isn’t as common in newer water heaters.

If you can’t find a matching flange element, look for an adapter kit. With this kit, you can replace the older flanged type with a modern screw type.

In most cases, you don’t need to purchase whole-specific proprietary parts.

Wattage and Voltage

Most residential water heaters use a 240-volt power source. The 120-volt elements are primarily used for smaller water heaters or in locations where 240V circuits aren’t available. Learn about what size breaker you need for your water heater to check that safe electrical connections.

The wattage rating for 240-volt elements tends to be anywhere between 6,000 watts and 10,000 watts. For 120V water heaters, the wattage rating is around 1,000 watts to 2,500 watts.

Every water heater model is designed for a specific wattage and voltage rated element. Your replacement element must be the same or equal wattage and voltage as the one you’re replacing.

Never go outside the nameplate rating on the water heater element. Using an element with higher wattage than specified can be dangerous.

Watt Density

The other critical factor to consider is the watt density construction of the element. Regardless of whether the element is 240V or 120V, bolt-in or screw-in, there are three watt density ratings available.

A water heater element’s watt density is the amount of heat focused at any point on the element’s surface. The lower the watt density, the greater the surface area of the element.

The heat per square inch of the surface is reduced, but the total surface is increased so that the total heat output remains the same for a given wattage. In general, a lower watt density means the element can last significantly longer.

Lower watt density elements perform especially well in water with high lime content. The fold-back design of many “lime life” and low watt density elements keeps the length short enough to fit all tank sizes.

What Is Water Heater Element Density?

Density refers to the surface area of the heating element. The greater the surface area, the lower the density classification.

A low-density heating element can slow deposit buildup and typically has a longer operational life. Below are the three standard watt density categories.

Regular High Watt Density Element

This is the most common water heater element. It’s the least expensive option and can be used in all replacements as long as the same voltage and wattage are matched.

Better, Low Watt Density Element

Most of these are “fold back” elements. They’re better suited for regions with water problems such as hard water, lime deposits, and mineral buildup.

The lower watt density doesn’t reduce effectiveness, but it significantly reduces lime deposit buildup. Low watt density elements can also be used to replace any high watt density element as long as the same voltage and wattage are used.

Premium, LimeLife Element

This is the top-tier option. It features a special metal surface, ultra-low watt density, and typically comes with a restricted five-year warranty.

The special surface metal reduces the chances of lime buildup. It may be costly, however it’s worth every penny.

It might even outlive the time of the heater.

Common Things to Keep in Mind Regarding Water Heater Elements

Common residential water heaters have two elements, but they don’t work at the same time. The upper element heats first, and then power transfers to the lower element.

The element is the most likely part to fail on an electric water heater. The hotter the heating element runs, the more sediment and metal buildup occurs within the tank. This buildup can also cause low water pressure and other performance issues.

If a new element makes a buzzing or vibrating sound, it’s usually because the loop on the element is positioned horizontally within the tank. Most elements can only function properly when fully submerged in water.

Factors That Determine How Much It Costs to Replace a Water Heater Element

How Many Elements Need Replacement

Your electric water heater tank has two heating elements: an upper element and a lower element. If one of them fails, you’ll notice lukewarm water instead of hot water.

If both elements fail, you’ll have no hot water at all. Replacing both elements costs more due to additional labor and components compared to changing only one.

The Heating Element Material You Choose

You can choose from three different types of element materials. High density elements are the least expensive and are made of copper coated with zinc, but they have a shorter lifespan due to corrosion.

Low density elements are mid-priced and made of copper coated with magnesium oxide and nickel. This coating makes them resistant to corrosion and gives them a longer service life.

Extra-low density elements are the most expensive and are made with stainless steel. These elements are naturally corrosion resistant and typically come with a lifetime guarantee.

The Contractor You Hire

More experienced contractors generally charge more for their services. However, they usually get the job done right the first time, preventing you from spending money on future repairs.

Verify that the contractor is licensed and insured before hiring. Check their business record and how long they have been operating. You can also learn whether a homeowner can install a water heater themselves to save on labor costs.

Ask whether they provide transparent pricing and are willing to give a written estimate. That’s a strong indication they will keep their word and not surprise you with hidden costs after the job is completed.

Single Element Water Heaters vs Dual Element Water Heaters

The dual-element water heater is a relatively recent introduction to the market. For a long time, the only electric option for consumers was a single-element water heater.

Once dual-element models hit the market, it became clear they were superior to single element models. Nowadays, nearly every modern home has a dual element water heater.

The two main reasons for their popularity are efficiency and cost savings.

Are Dual Element Water Heaters More Energy Efficient?

One major reason for the popularity of dual element systems is that they heat water quickly and efficiently.

Single element water heaters only have one heat source situated near the bottom of the tank. It takes longer for the water at the top to heat up, which can be a problem if you run out of hot water.

Dual element water heaters solve this problem. The two heating elements coordinate with each other to make sure there’s always hot water at the top of the tank.

If the water temperature at the top drops below the upper thermostat setting, the top element activates. Once the upper water reaches the specified temperature, the top element shuts down and the bottom element takes over.

The bottom element then heats the rest of the water in the tank to the desired temperature. In short, the top element makes sure hot water is available quickly so you don’t have to wait hours for a shower when someone uses all the hot water.

The bottom element helps with the majority of the water sitting in the middle and bottom of the tank gets heated. This means you’ve a bigger supply of hot water once the lower element completes its heating cycle.

Can Dual Element Water Heaters Save Money?

The other benefit of a dual element heater is that it usually costs less to operate than a single element heater. The dual-element system uses less energy overall than a single element system.

You’ll likely notice some savings on your monthly electric bill. However, one should note that dual-element maintenance can be more costly than single element maintenance.

This is simply because there are more components to replace. It can also be slightly more complex to replace an element on a dual element system because the top and bottom elements are two separate devices.

If the top element fails, you need to replace it with another top element. You can’t use a bottom element to replace a broken top element because these two aren’t interchangeable.

Most technicians will also recommend changing the thermostat when the upper heating element is replaced.

Will a Water Heater Work if One Element Fails?

Modern water heaters are designed with the thermostat connected to the top element. If the top element fails, the thermostat won’t allow the bottom element to run, even if the bottom element is in perfect condition.

However, if the bottom element fails, the top element can still work. The hot water supply will decrease significantly, resulting in a small amount of hot water followed by warm water and then cold water.

Heating Element Problems That Are All Too Common

Failure in an electric water heater may be the result of a different component’s defect within the system. A heater that has issues needs repair service on time to keep the problems contained.

When your electric water heater isn’t providing enough hot water or fails to heat completely, you likely have a defective heating element. This is a relatively common problem with several possible causes.

The Heating Cycle

A water heater tank contains two heating elements that perform heating roles separately. Each is connected by individual thermostats.

In a hot water system, a tube supplies cold water to the bottom of the tank. As you use hot water, the level drops and triggers the cold water supply, which cools down the lower thermostat and causes the corresponding element to activate.

Looking at this cycle, any defect in one of the heating elements means trouble for your entire heater.

Broken Elements

A common reason for element failure is breakage due to consistent heating and cooling cycles. Over time, cracks appear on heating elements and cause a decline in heating performance.

After a passage of time, cracks appear on heating elements causing impacts on heating performance.

Faulty Thermostats

Damage to the thermostat is another reason behind element failure in water heaters. A thermostat controls the temperature settings that a heating element uses to provide its heating.

With a faulty thermostat, a water heater tends to supply water that’s too hot or not hot at all. A faulty thermostat is also a common reason your water heater keeps turning off. Sometimes, heating elements are simply too old to perform properly and need replacement, and the same goes for thermostats.

Getting the Right Water Heater Element

Not all heating elements are created equal. You need to know the exact specifications of your heating element to get an adequate replacement.

Check whether your element is mounted with screws or bolts. Modern elements are typically screw-in, but it’s good to verify your setup.

Remember that top elements and bottom elements are entirely different devices. You can’t replace a top element with one designed for the bottom, and vice versa.

Make sure the wattage of the replacement element is less than or equal to the wattage of your current element. Never purchase a replacement with a higher wattage than what your water heater is rated for. Understanding how long a 50-gallon water heater lasts can also help you decide between element replacement and a full unit upgrade.

Finally, determine whether your current element is a high watt density, low watt density, or lime life element. Upgrading to a lower watt density or lime life element can extend the time between replacements. If you’re considering alternatives to a traditional tank heater, explore whether point of use water heaters are efficient for your needs.