If you have an electrical water heater, it’ll have heating elements responsible for raising the water temperature. But if the elements burn out, the water won’t get heated and come out cold.
As such, it’s essential to understand why your water heater elements are burning out, so you can stop it from happening and enjoy a nice warm shower.
Water heater elements burn out because of sediment buildup on the heating elements. It can also burn out due to a power surge, air pockets inside the tank, or wiring or electrical faults.
In this article, I’ve put together an in-depth look at the major reasons heating elements on water heaters burn out. Then, I’ll share a detailed look at how you can know for sure whether your heater elements are faulty — and if they are, how to replace them.
Reasons Why Water Heater Heating Elements Burn Out
Here’s why your water heater heating elements burn out:
- Sediment buildup on the heating elements
- Recent power surge
- Air pockets inside the water heater tank
- Wiring and electrical faults
Let’s go over each of these points in more detail.
Sediment Buildup on the Heating Elements
Do you run hard water into your water heater? If so, it can lead to sediment buildup in the heating elements, causing them to burn out. See, hard water contains significantly more minerals like calcium and magnesium in a dissolved state.
However, as the water heats up, the minerals return to their solid state and start to settle down, creating sediment layers inside the water tank.
Over time, the heating elements also get covered by the sedimentary deposits, which create an insulating layer. This layer will eventually get thicker, making it difficult for the heating elements to properly heat the water inside the tank.
The heating elements need to work harder to heat the water to the desired temperature. This puts extra pressure on the elements, eventually causing them to burn out or fail.
Now, damage from sediment buildup happens most frequently with the bottom element as sediment sinks and gathers near the bottom of the tank.
Thankfully, you can easily avoid sediment buildup in your water heater by draining the water tank every few months and wiping it clean to ensure that nothing gets left behind that can cause sediment buildup.
Also, mineral deposits usually happen when the water is heated beyond 120°F (49°C). As such, you should avoid heating the water beyond that temperature.
You can also try using water softeners like the Morton Salt Pure and Natural Water Softener Crystals (available on Amazon). It’s NSF-certified and will help extend the life of your water heaters by softening your hard water.
Recent Power Surge
Did your water heater element burn out following a power surge? If yes, that might be the reason it failed. Your electric water heater is rated to operate at a particular voltage, as shown by its voltage rating. If it receives more voltage than it can handle, that can damage the internal components, including the heating elements.
Unfortunately, there’s no way to prevent a power surge. They’re more common in some areas than others. Usually, power surges happen during lightning storms or if your power company experiences a surge. It can also happen because of faulty wiring inside your home.
That said, you can take steps to protect your home appliance from damage due to a power surge.
For starters, you can install a surge protector for your water heater — or better yet, your entire home. Call an electrician to decide what type of surge protector best fits your needs and budget and have it installed.
While you have the electrician over, have them check your home wiring for any faults or issues — whether it’s related to your water heater or not. If they come across something, get it fixed as soon as you can.
Lastly, as a precautionary step, unplug your water heater during a lighting storm to prevent potential power surge issues.
Air Pockets Inside the Water Heater Tank
The water heater is designed to function when the water tank is filled with water, and the heating elements are completely submerged in that water.
However, sometimes air pockets can develop inside the water tank. These air pockets will naturally displace the water at the top of the tank and settle near the top heating element, exposing it to air.
That can cause a huge problem.
You see, the heating element can reach extremely high temperatures. As such, they need to be fully submerged in water to efficiently transfer the heat away from it and avoid damaging the unit.
When the top heating element is exposed to air without any contact with water whatsoever, it’ll heat up drastically. This temperature rise can potentially burn out the core of the element in seconds — something known as a dry-fried element.
Here’s a quick YouTube video demonstrating dry fire in heating elements:
Now, if you have a dry-fried heating element, you’ll have no choice but to replace it.
However, you can take precautionary steps to ensure such an incident doesn’t happen again.
First of all, air pockets won’t randomly form inside the water heater. It forms when there are leaks or issues with the piping. If you have air pockets in the water tank, call a plumber to troubleshoot how the air is getting in and then have them fix the problem.
Also, air pockets can form if the tank wasn’t correctly drained out after the water heater installation or any other repair work. If the installation mechanic or the repairman forgot to drain out the water heater, you can do it yourself.
Here’s a step-by-step guide on how to remove air pockets from a water heater:
- Turn on the cold water feed, so it starts filling the tank.
- Open the pressure relief valve until you see water coming out, and then turn it off.
- Turn on the hot water outlet valve on the water heater and then turn on every faucet in the house to the hot-water side.
- Let the water flow through the faucet to remove all air out of the tank. You’ll know there’s no more air when you notice a steady clear stream of water from all faucets.
Now, you can turn on the water heater without worrying about having dry-fried elements.
For reference, here’s a short 2-minute YouTube video on how to remove trapped air out of a water heater:
Wiring and Electrical Faults
Lastly, you shouldn’t forget that your water heater is an electrical appliance, and as such, it’ll get damaged from wiring or electrical faults. For instance, if there’s a poor connection between the wires and the water heater, it can cause the heating elements to fail or burn out.
Likewise, if the hot wire gets grounded to the metal tank, it can also cause the heating elements to burn out. What’s more, this situation can create a potential shock hazard and is something you should get checked out as soon as possible.
Now, if you wish to troubleshoot your water heater for electrical faults, you should turn off its power supply. I’d even recommend you turn off the connected circuit breaker to be safe.
Remember, a water heater is a high voltage appliance, and you need to play safe. Otherwise, you can end up electrocuted.
This is why I strongly urge people who don’t have experience with electrical appliances to call a professional and have them check your heater for wiring and electrical faults.
Signs That Your Water Heater Elements Have Burnt Out
Your water heater has two heating elements — one on the top and the other one on the bottom.
If the top heating element fails or burns out and the bottom one works fine, you’ll get the following symptoms:
- The hot water coming out of the heater isn’t as hot as the temperature you set it to.
- Only a small amount of hot water is coming out.
On the other hand, if the bottom element fails and the top one is okay, you’ll notice the following:
- The hot water runs out faster than before.
- There’s no hot water in the tank.
If both heating elements fail together:
- You’ll get no hot water.
- The circuit breaker for the water heater keeps tripping.
That said, all of these symptoms can also happen if some other component of your water heater fails.
As such, I’d recommend you run a continuity test to make sure the heating elements are working. For that, you’ll need a multimeter like the AstroAI AM33D Digital Multimeter (available on Amazon), which is perfect for testing common household electronic appliances.
With the multimeter in hand, follow the given steps:
- Shut off power to the water heater. Turn off the connected circuit breaker to be safe.
- Remove the metal panel(s) covering the thermostat and the heating elements.
- Move the insulation sheet and the plastic safety panel.
- Adjust the multimeter to the resistance or ohm setting and turn it to the lowest value.
- Touch the probes on the multimeter against the screws on the heating elements.
If you get a reading between 10-30 ohms, that means the heating elements are working fine.
However, if you’re reading 0-1 ohms, the heating elements are faulty, and you need to replace them.
How To Replace Heating Elements of a Water Heater
If the heating element in your water heater is busted, you’ll have to replace it.
It’s important to note that water heaters operate using high voltage. As such, I strongly recommend that if you’re not experienced in handling electrical appliances, you should call a professional to help you install the replacement water heater.
That said, if you’re confident and skilled enough to handle this DIY project, I’ve put together a detailed step-by-step guide on replacing the heating elements of your water heater.
But first, you’ll need to get your hands on the specific type of replacement heating elements that’ll work with your water heater. For that, I suggest you check the user manual or paperwork that came with your appliance.
Alternatively, you can also contact a technician or a repair shop to buy the necessary parts.
Once you have the replacement heating elements, follow the given steps:
- Turn off the circuit breaker to which the water heater is connected.
- Turn off the cold water feed.
- Open the pressure relief valve and drain out all the water inside the water heater tank.
- Unscrew the access panel, move the insulation, and remove the plastic safety panel covering the heating elements.
- Unscrew the wire assembly connected to the heating elements.
- Dislodge the old element and take it out of the water heater. You’ll either have to unthread any mounting screws or use a socket to unscrew the entire heating element and take it out.
- Install the new heating elements and mount them in place.
- Secure the wire assembly to the new elements.
- Cover it up with the plastic safety panel, followed by the insulation layer and the access panel.
- Bleed out the water tank to ensure there is no trapped air inside it.
- Once all the air is out, you can power on the water heater.
Note: It’s important to remove the air from the tank before turning on the water heater, or the trapped air can damage the top heating element.
And that’s it! You’ve successfully replaced the heater elements on your water heater.
In case you’re more comfortable following a video tutorial, here’s a 9-minute YouTube video on replacing heating elements of a water heater:
Key Takeaways
The most likely reason the heating elements in your water heater burned out is sediment buildup. Other potential reasons include a recent power surge, trapped air pockets inside the water tank, and wiring or electrical faults. To prevent such mishaps, you need to regularly drain out the water tank, install a surge protector, and provide routine maintenance to ensure the wiring and piping are all okay.
Steve Rajeckas is an HVAC hobbyist with an avid interest in learning innovative ways to keep rooms, buildings, and everything else at the optimal temperature. When he’s not working on new posts for Temperature Master, he can be found reading books or exploring the outdoors.