Replacing your water heater element can be a confusing process – there are so many lumps of metal that all look the same and purportedly do the same function, but why is everything surrounded by so much jargon?
We have put together this handy guide to take you through the essentials of water heater elements.
Are all water heater elements universal? – Quick guide
As a blanket statement, this is incorrect. You cannot randomly select an element and be guaranteed that it will work in your heater.
You must choose the element with the correct wattage and voltage for your heater, or the element will not be compatible and the entire system will not work.
You also need to consider the shape of the element. Most modern heaters use a screw in flange type which will be universal in terms of shape and shape alone.
So, if you narrow down your choice of heater elements to ones that are the correct shape, wattage, and voltage, these are all interchangeable with each other. Any element that fits these criteria will fit into your water port and work fine in the system.
Other factors, such as wattage density, can be considered but will not have a great impact on the overall compatibility of your selected element.
Water heater elements can be split into three categories. These are bolt in, clamp on, and screw in. The most commonly used in a domestic setting are the screw and bolt varieties. They each have different wattages but all work on a 120 or 240 voltage system.
Screw In Heating Elements
This is the most common type of heating element and is the standard default on all new water heaters. These elements work by being screwed into place and are the most simple to install.
Bolt In Heating Elements
There are a few subdivisions of bolt in heating elements and they are more common in older water heating systems. Generally, four bolts hold the heating element in place.
If you need to adapt a screw in heating element into a bolt in port, you can purchase universal adapter kits to make this possible.
Choosing the Right Water Heating Element
Three factors determine which type of heating element is best for you.
Firstly, the element’s flange style. Modern heaters all use screw in elements in a domestic setting and these are all interchangeable. This is because the threading on the element and the port is standard, making installation simple and servicing stress-free.
Previous incarnations of water heating elements, however, have utilized numerous flange styles over the years. These include the universal flange, the flat flange, and the round head style flange.
The universal and flat flange elements are all fixed in place by four ⅜ inch bolts. The round head flange, however, is bolted into place with a separate four-bolt flange.
Voltage And wattage
The overwhelming majority of water heaters for residential properties use a 240V power source, with 120V water heaters used for small tanks or where 240V is not available for whatever reason.
For a 240V water heater, you can go for an element that is anywhere from 6,000 to 10,000 watts. If you have a 120V water heater, you can choose an element that has a wattage of 1,000 to 2,500.
Be aware that your water heater will have been designed for a specific wattage and voltage and you, therefore, cannot randomly select a new element to install. It must have the correct wattage and be suitable for the voltage of your heater.
Check that the replacement element has an equal wattage to the old one and that the voltage is correct. Check with the manufacturer if you are unsure at any point.
This controls how much heat is put into any specific point of the element’s surface, with a low watt density element will use less wattage relative to its size than a high watt density element. There are three watt density ratings available on the market and, much like wattage and voltage, your replacement element must correlate with the old one.
If an element has a low watt density, the element is going to have a longer life in your water tank. This is because a low watt density element can easily operate at a much lower temperature than a high watt density element, causing less damage to the heating unit as a whole.
Be aware that any element will last longer in water with a high lime content. A low watt density element in high-lime-content water will therefore last well over a decade.
The three watt density options available for elements are:
- High watt density – these are the cheapest option available and can be put into any water tank that is the correct voltage and wattage.
- Low watt density – these are better for homes with hard water and are compatible with any water tank at the correct voltage and wattage.
- Premium elements – these are made with an extremely low watt density, often a five-year to lifetime guarantee, and are designed with a unique metallic surface that dramatically reduces lime build-up. These are the most expensive available but often outlive the heaters they are placed in.
Providing you select elements that are the correct wattage, voltage, and flange style, you can put any one in your heater. If any of these aspects of your element selection is not correct, your water heating unit will not work.
For the best results, try to find an element that is the same as or is as closely related as possible to the element you need to replace.
Frequently Asked Questions
Are All Water Heater Elements Universal?
No, they are not. You need to make sure you choose the correct wattage and voltage for your water heater as well as the correct flange style for your tank. Many modern systems are standardized which makes things easier, but caution must still be exercised.
How Much Does Replacing A Water Heater Element Cost?
This will depend on the type of heating element you choose and the contractor you hire. Spending more money on a contractor with the best experience and qualifications is a good idea as you are less likely to experience problems down the line. Make sure that you check their insurance and other required authorizations for your state before they begin!
Low density wattage elements will last a lot longer than their high density counterparts, and this longevity is reflected in their price. Extra-low density options are now available that are again more expensive but offer a lifetime guarantee.
If you can budget for a heater element with the longest life you should go for it – you won’t need to have the element replaced again for another few decades which means no more contractor invoices and will be cheaper in the long run.