Why Does Your Water Heater Smell?

Erin Easley

Written By Erin Easley

Published 10/05/23
Water Heater Smell

Often, the most important and frequently used resources in our homes are the ones we take most for granted. We rely on fresh, potable water for countless daily activities. We need it to drink, cook, bathe, brush our teeth, wash our hands, clean our homes, launder our clothes—the list goes on. Unclean or foul-smelling water is a major nuisance at best and health hazard at worst.

A common source of water woes is actually your home’s water heater. Various issues, from mechanical failures to bacteria build-up, can make for a stinky water heater. In this post, we’ll review some common reasons why your water heater smells.

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What Causes Water Heater Smells

The kind of smell you notice from your water heater is the best clue to help you diagnose the problem. Here are some common causes.

1. Faulty Wiring

Electrical water heaters are susceptible to shorts. Occasionally, loose wires come in contact, generating heat. If your water heater is suffering from such an issue, you may notice the smell of a burning wire. If the wire’s insulation begins to melt, it might smell like burning plastic.

This kind of water heater malfunction will usually come on all of a sudden. If it appears your water heater has an electrical problem, don’t attempt to resolve the issue yourself. First unplug your water heater to avoid a fire or further damage. Then, if you have water heater home warranty coverage, submit a claim with your provider. If you don’t have coverage, call a trained technician.

2. Gas Leaks

As with any gas-fueled appliances, gas water heaters can develop a leak. If you smell gas in the vicinity of your water heater, shut off your appliance and immediately call the fire department. If you know how to shut off the gas to your home or appliance, do so. But don’t fuss with anything unless you know exactly what you’re doing. Once the gas is shut off and safety is ensured, contact your warranty provider or a repairperson to fix your water heater.

3. Dirt and Dust

Older water heaters can accumulate dust, dirt, and grime. If dust or debris contacts a warm part of the machine, you may notice a burning smell. This is usually an easy fix. Shut down your water heater if it’s too hot to the touch. Then wipe clean with a damp cloth. If the smell persists, contact a professional.

4. Sulfate Bacteria

Many homeowners notice the smell of sulfur or rotten eggs emanating from their water or water heater. This is due to a proliferation of sulfate bacteria in your water heater or water source. If you notice the sulfur smell even when cold water runs from the tap, the problem is at your water source (your well, for instance, may need chlorine treatment). If you notice the smell only when running hot water, your water heater is the problem.

Here’s how to prevent plumbing sulfur smells. If you’re the DIY type, flush and disinfect the inside of your water heater’s tank. Then replace your tank’s anode rod. Of course, a plumber can handle this task instead. If the smell persists, you may need to replace your tank.

Health Implications: Is Smelly Water Harmful?

A common concern when dealing with smelly water is whether it poses any health risks. In most cases, the odors themselves are not harmful, but they can indicate the presence of certain substances or conditions that might be problematic:

  • Hydrogen Sulfide: The rotten egg smell due to hydrogen sulfide gas is generally not harmful in low concentrations. However, it can make water consumption and daily activities unpleasant. Extremely high concentrations of hydrogen sulfide can be toxic and should be addressed immediately.

  • Bacteria and Microorganisms: The presence of bacteria and microorganisms in your water heater can indicate potential contamination, so it's essential to address it promptly to ensure safe water usage.

  • Chemical Reactions: Odors resulting from chemical reactions might not directly harm your health, but they can indicate corrosion or damage to the water heater, which should be addressed to maintain safe operation.

While the odors themselves may not be hazardous, it's crucial to investigate and resolve them to ensure the safety and quality of your hot water supply.

Identifying the Source: Is It the Water or the Heater?

Before implementing any solutions, it's important to determine whether the odor originates from the water source or the water heater itself. Here's a simple test to help you differentiate:

Test 1: Cold Water vs. Hot Water

  • Run both cold and hot water separately from your taps.

  • Smell the water from each tap.

  • If the odor is only present in the hot water, it's likely an issue with your water heater. If it's present in both hot and cold water, the problem may be in the water source or plumbing.

If the odor is isolated to the hot water, proceed to the next sections for solutions specific to water heater issues.

Preventing Future Odors: Maintenance and Best Practices

Prevention is often the best approach to avoid water heater odors in the future. Here are some maintenance tips and best practices:

  • Regular Flushing: Periodically flush your water heater to remove sediment and bacteria. How often you should flush it depends on your water quality; annual flushing is a good starting point.

  • Inspect the Anode Rod: Check the condition of the anode rod annually and replace it if it shows significant corrosion.

  • Maintain Adequate Temperature: Keep the water heater thermostat at or above 120°F (49°C) to discourage bacterial growth.

  • Use a Water Softener: If you have hard water with high mineral content, consider installing a water softener to reduce sediment buildup.

  • Regularly Clean and Disinfect: Occasionally clean and disinfect the tank to prevent chemical odors.

When to Seek Professional Help

While many water heater odor issues can be resolved through DIY methods, there are situations where it's best to seek professional assistance:

  • If you're unsure about the cause of the odor.

  • If the smell persists after attempting DIY remedies.

  • If you notice leaks, unusual noises, or other signs of water heater malfunction.

  • If you have an older water heater that may require a thorough inspection or replacement.

Professionals can conduct thorough assessments, perform repairs, and recommend the most suitable course of action based on the specific issues with your water heater.


Does Home Warranty Cover Water Heater Repair and Maintenance?

The effects on water from water heater smells negatively affect your quality of life. A safe, livable home needs reliable access to fresh water.

Water heaters are complex machines, and it’s hard for the layperson to diagnose and resolve most problems. That means spending hundreds in plumbing or electrical repair. Fortunately, you can shield yourself from these surprise costs with home warranty coverage.

Liberty Home Guard can protect your water heater, no matter the make or model. You can also bundle coverage to protect your other home systems, from plumbing and electrical to HVAC and more. Call us at (833)-544-8273 to get started.

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