What Causes Heating Elements to Burn Out?
As a home improvement expert who has renovated hundreds of bathrooms and kitchens over my career, one of the most common appliance repairs I encounter is burned out heating elements. Given how often heating elements fail, it‘s helpful for any homeowner to understand what causes these important components to stop working properly.
In this comprehensive guide, I‘ll share my insight on:
- How heating elements work and where they‘re used
- The top causes of heating element failure
- How to extend the lifespan of your heating elements
- Signs that your element may be failing soon
- Step-by-step troubleshooting tips
- Detailed instructions for replacement
- When it‘s best to call in a professional
As we dive in, I‘ll provide helpful statistics, maintenance tips, and examples from my years of experience replacing hundreds of worn out heating elements. My goal is to ensure you feel completely confident diagnosing and addressing any heating element problems that may arise in your home.
Overview of Heating Elements
Before we get into what causes heating element failure, let‘s briefly overview how they work.
Heating elements contain coiled metal wiring, typically nickel-chromium alloy or steel, that‘s enclosed in a metal casing. As electric current passes through the coils, the resistance causes rapid heating. Temperatures can reach well over 500°F!
Ceramic insulating materials help prevent electrical shorts and dissipate some excessive heat. The metal sheathing meanwhile protects the inner wiring and allows for convenient mounting in appliances.
Here are some of the most common locations for heating elements:
Electric Ovens
Electric ovens have two heating elements – one at the top and a larger one at the bottom. The bottom element often supplies 70-80% of the heat for baking. The top element functions more for broiling.
Electric Dryers
A long coiled heating element is located behind the tumbler to warm the air that circulates through the clothes. It typically only turns on periodically during the cycle.
Electric Water Heaters
Units have 1 or 2 screw-in heating elements at the bottom or sides of the tank. As water passes by the elements, it gets heated.
Space Heaters
Space heaters have exposed heating coils that warm the surrounding air via direct radiation and convection. Ceramic insulation prevents contact burns.
Now that you know a bit about how ubiquitous heating elements are, let‘s look at the top reasons they ultimately fail.
What Causes Heating Elements to Fail?
Based on my repair experience, these are the most common causes of burn out:
1. Age and Long-Term Wear
The repeated expansion and contraction of the metal coils caused by heating and cooling cycles over many years leads to material fatigue and embrittlement. The wiring and connections become increasingly fragile over time.
Statistics show the average lifespan of a heating element is 5-8 years, but they can last over a decade with proper maintenance. Either way, an older heating element is much more prone to failure than a newer one.
2. Mineral Buildup
Hard water rich in minerals like calcium and magnesium takes a major toll on water heater elements. During heating cycles, the minerals solidify on the metal coils as scale.
This insulating mineral layer reaches temperatures hotter than the coil itself! I‘ve seen scale deposits over 1/4" thick completely encasing elements after just a few years. All that overheating forces early failure.
3. Corrosion Damage
Corrosion from acidic water or harsh chemicals eats away at the metal alloy heating coils and wiring contacts. Pool and spa heaters are especially vulnerable to corrosion. But even small amounts of chlorine and other chemicals in tap water will eventually cause corrosion. The damage makes elements more fragile and prone to failure.
4. Power Surges
Spikes in current from events like lightning strikes, damaged power lines, and malfunctioning appliances can instantly overload heating elements and cause burnout.
In one house I renovated, a failing A/C unit sent a massive power surge through the home, destroying heating elements in the oven, water heater and more all at once! Using a whole home surge protector prevents such catastrophic damage.
5. Installation Mistakes
It‘s remarkably common for do-it-yourselfers and even some repair technicians to improperly install replacement heating elements.
For example, overtightening the mounting screws can deform the housing, loosening them leads to vibration damage, applying too much sealant compound blocks heat transfer, and using the wrong voltage element frequently causes premature failure.
6. Manufacturing Defects
While rare, I‘ve encountered brand new heating elements with physical defects right out of the box. Shoddy quality control can unfortunately allow flaws like thin spots in the coils or cracks in the insulation to slip through. This leads to early failure once put into service. Reputable brands have lower defect rates.
7. Sediment Buildup
In water heaters, scale isn‘t the only issue. As water naturally evaporates from the tank, dissolved solids drop out of solution and gradually form sediment mounds. If allowed to build up excessively, sediment will surround heating elements acting as insulation. This forces them to overheat trying to transfer heat through the barrier.
8. Excessive Cycling
When heating elements rapidly turn on and off, the quick expansion and contraction strains the components. I once saw a faulty thermostat causing an oven element to cycle on and off every few minutes. This extreme thermal stress led to the coils quickly cracking and breaking. Excessive cycling is especially damaging.
9. Blocked Air Flow
For heating elements relying on air circulation like in dryers and space heaters, restricted airflow causes significant overheating.
Lint trap buildup, crushed dryer vents, and blocked space heater air intakes are common culprits I find during repairs. Without a strong airflow, elements cycle too hot for too long trying to maintain the target temperature.
10. Overloading
Drawing too much electrical current through an undersized heating element leads to overheating damage. For example, I once received a frantic service call about an oven that wasn‘t heating properly. The owners had stuffed multiple large turkeys in together for Thanksgiving! That extreme overload fried the element.
Signs of a Failing Heating Element
Based on the hundreds of repairs I‘ve completed over the years, watch for these early warning signs of impending element failure:
- Unusually long heating times
- Appliance unable to reach target temperature
- Food cooking unevenly
- Scorch marks or discolored metal
- Damage like cracks or bulges
- Overheating (burn risk)
- Odd smells from burning dust or grease buildup
- Loud popping or buzzing sounds
- Tripped circuit breakers
- Dimming lights or flickering bulbs in the home
If you notice any of these issues, it‘s smart to thoroughly inspect your heating elements before problems worsen. Early intervention can save you money and prevent further appliance damage.
Next, let‘s go over some of my top tips for extending the lifespan of your heating elements and avoiding premature failure.
How to Extend the Life of Heating Elements
Proper maintenance is absolutely key to maximizing the years you‘ll get out of your heating elements. Here are my professional recommendations:
Avoid Overloading Elements
Don‘t exceed the oven temperature or load capacity recommendations. Overloading causes rapid deterioration. Upgrade your electrical service if needed to handle larger loads.
Inspect Wiring Frequently
Check the wiring leading to heating elements and all connections for damage. Look for discoloration, cracked insulation, loose terminals, and corrosion. Address issues immediately to prevent failure.
Clean Elements and Appliances Regularly
Remove built up grease, lint and any mineral deposits to prevent overheating and prolong element life. Carefully scrape off any scale on water heater elements.
Ensure Adequate Airflow
For heating elements relying on air circulation, keep vents, ducts, filters and intakes clean. Blockages make elements run dangerously hot.
Consider a Surge Protector
Power surges from storms or faulty equipment destroy countless heating elements every year. Protect expensive appliances with a surge protector.
Drain Water Heaters Annually
Sediment buildup reduces efficiency and accelerates wear. Flushing water heaters yearly reduces scale and prolongs element life.
Have an Electrician Inspect Wiring
An electrician can identify any wiring issues leading to elements, diagnose electrical problems, and confirm appliances are operating safely.
Shut Off Units When Away
To reduce wear, turn off water heaters, hot tubs, and other equipment with heating elements when leaving home for extended periods.
Monitor for Leaks
Leaks allow corrosive water to damage heating elements and wiring. Promptly repair any drips orwet spots.
Test Safety Valves Yearly
Faulty pressure and temperature relief valves can lead to catastrophic overheating when elements malfunction. Maintain valves properly.
Consider Water Softening
In hard water areas, water softeners dramatically reduce scale buildup helping heating elements last longer.
Staying on top of maintenance and avoiding misuse pays dividends by keeping heating elements in optimal operating condition for maximum longevity.
Troubleshooting Heating Element Failures
When an appliance with a heating element stops working properly, here are the steps I take to diagnose the issue:
1. Check Power Supply
First, I verify the unit is getting power by testing outlets, breakers, fuses and other electrical components. Restore power if needed.
2. Test Element Continuity
Once power is confirmed, I disconnect the element and check continuity across its terminals using a multimeter. No continuity means the element itself has failed.
3. Inspect for Damage
Next, I remove the element and visually inspect for cracks, melted spots, corrosion, mineral buildup or other damage. I compare it to a new element to identify degradation.
4. Check Wiring Condition
I inspect the wiring leading to the element for any insulation damage, loose connections, or signs of overheating. Damaged wires can prevent proper operation.
5. Ensure Safety Components Function
I test any related safety components like thermostats, thermal fuses, door latches and high limit switches for correct operation. A defective safety component could be causing issues.
6. Verify Installation
If needed, I‘ll reinstall the suspect element and monitor appliance operation to check for uneven heating, slow recovery, overheating or other problems potentially related to faulty installation.
7. Replace Damaged Elements
If I confirm the heating element itself is defective through testing, I replace it with an identical part from the manufacturer. I verify normal operation before closing up the repair.
Thoroughly troubleshooting heating elements saves homeowners money by only replacing failed parts. It also ensures additional problems aren‘t overlooked.
Safely Replacing a Burned Out Heating Element
When you need to replace a faulty heating element, exercising caution is critical. Based on my experience, follow these safety tips:
Disconnect Electrical Power
Always switch off the circuit breaker or unplug the appliance before starting any work. With heating elements, I recheck with a non-contact voltage tester to be absolutely sure.
Allow Components to Completely Cool
It‘s crucial to let heating elements, insulation, housings and other nearby parts cool for 1-2 hours. Old ovens and water heaters often take much longer to reach a safe temperature.
Use Protective Gear
Wear insulated gloves rated for appliance electrical work along with eye protection. Long sleeves and long pants provide protection as well from adjacent hot components.
Follow Appliance Manuals
Manufacturer directions provide model-specific procedures for safely accessing and replacing heating elements. Follow all instructions closely.
Photograph Wiring Connections
Take photos of all wiring terminal positions before disassembly. This provides an invaluable reference to ensure error-free reassembly.
Clean Mounting Surfaces
Remove any debris, insulation scraps or old putty from the heating element cavity before installing the replacement. Proper mating is essential.
Use Properly Rated Tools
Heating element wiring is fragile. Use insulated tools rated for appliance electrical work to avoid damage during removal and installation.
Confirm Normal Operation
Test the appliance for 10-15 minutes after replacing the element to verify proper heating and normal operation before returning to service.
Inspect Safety Systems
Double check that high limit switches, thermostats, door latches and other safety systems function correctly before using the repaired appliance.
Meticulously following safety procedures reduces the risks of electrical shocks, burns, and costly damage to components or your home. I never take shortcuts when dealing with heating element replacements.
When Should You Call An Appliance Repair Technician?
While some basic heating element repairs are manageable for homeowners, it‘s best left to professionals for:
– Complex Appliances Like Ranges
Safely accessing elements in intricate appliances like double ovens is extremely difficult without commercial training and specialized tools.
– Troubleshooting Heating Issues
If you‘ve checked the obvious causes and the appliance still doesn‘t heat properly, a technician can pinpoint the real issue.
– Tight, Enclosed Element Locations
Removing and replacing elements wedged into tight spaces often requires partial disassembly that‘s best left to technicians.
– Gas Appliances
Leave gas appliance repairs to certified experts. Improper work risks dangerous leaks and explosion hazards.
– High Voltage Equipment
Electric ranges and other high voltage appliances pose electrocution risks during internal repairs. Exercise extreme caution.
– Verifying Appliance Safety
Technicians perform detailed safety checks of all components to ensure appliances function properly after element replacements.
Don‘t take risks tackling complex appliance repairs. Trust certified local pros like myself to do the job safely and correctly.
Key Takeaways on Heating Element Failures
To summarize this guide on the causes of heating element failure:
- Age, wear, scale buildup, corrosion, power surges and more progressively damage elements over time
- Warning signs of failure include slow heating, scorch marks and loud popping noises
- Preventative cleaning and maintenance dramatically extends element lifespan
- Replace failed elements with identical OEM parts for safety and proper operation
- Always disconnect power and allow appliances to fully cool before service
- For major repairs, trust certified appliance technicians for your safety
Conclusion
I hope this detailed overview gives you confidence in diagnosing and resolving any heating element problems that pop up in your home. While heating elements eventually wear out and burn out from years of use, proper installation and maintenance really helps maximize their longevity. Catching issues early before catastrophic failure allows for quick, inexpensive replacements.
For particularly tricky heating element repairs, or if you ever feel unsafe tackling electrical repairs, never hesitate to call certified pros like myself. We have the skills, tools and experience to get your appliances back up and running quickly and safely. I‘m always happy to help homeowners keep their kitchens and laundry rooms operating at peak performance!