8 Reasons Why Your Water Heater Smells Like Burning

Common Electric Water Heater Problems and Fixes

Your heating needs change with changing seasons. As you turn on your water heater for the first time in a long time, you will notice an unusual smell from the heater. The strange smell is like burning plastic. Is this smell harmless? Do you need to be concerned? Despite how you choose to react to this strange smell, you need to get to the bottom of this issue and fix it before it gets out of hand.

If you are using a gas water heater, you have to carry out a full diagnosis of the heater and fix all leaks that you find. Leaking gas is not only dangerous but may also affect your health negatively. However, if the smell is from an electrical fire, you should get a professional to check and repair the electrical wiring. Learn more about water heaters releasing burning plastic smell and how to deal with it.

How Does a Water Heater Work?

A metal holding tank is fitted to the conventional water heater. The holding tank is where the heated water sits. In most cases, this tank is made of steel because of its strength. When the source of heat to the heater is turned on, the tank begins to build pressure. If your appliance is not made of good quality material, it might break down during this process. You, therefore, have to ensure that you buy the best quality product in the market.

There are three main sources of heat for the water heater. These are natural gas, electricity, and propane. The electric heaters use a magnesium rod inside the water tank while propane and natural gas heaters use gas to start the fire. In both cases, two pipes are fitted to the water heater to transfer cold water from an intake pipe through the exit pipe’s oven to its exit point.

Why Your Water Heater Smells Like Burning

It is not usual for a water heater to smell like burning plastic. However, if it does, you have to inspect it for possible faults in the system. Here are some of the reasons why your water heater smells like burning plastic.

1. Contacts Overheating

If you can smell burning rubber or plastic from your, chances are your contacts are overheating. These are likely to be the contacts located on the thermostat outside of the water heater – when they overheat, they can give off a burning plastic smell. Another thing that could be giving off the plastic burning smell is the insulative coating on the wires. When they overheat, they can give off a burning smell. When these get old or they’re not installed properly, they can give off a burning smell. To fix this, you need to replace the installation or keep the plastic away from the heating element on the thermostat. If this is too foreign for you, then you’ll have to get someone professional to do the job for you.

2. An Electrical Burn

Most electrical burns are odorless, but if you’re smelling burning from your water heater, especially if it’s new, then it could be an electric burn that can usually smell like burning plastic. This typically happens when something that carries a current is overloading or the circuit in the wiring has shorted. A contact could also be overheating or the fire rod is failing.

As soon as you smell this, you need to check if there’s an issue with the wiring – you want to check the wiring for arcing. Also, check that the plastic is still intact around the wiring. If the contacts are overheating, then it means that the is generated at the connections which aren’t good. Excess current can also short circuit when the fire rod is failing. This can cause a burning smell to come from the wiring and thermostat due to heating.

Whatever may be the case, you need to fix the problem if you know what you’re doing. If you’re unsure of what you’re doing, then you need to get a plumber in to repair the wiring or advice you on whether you need to replace the water heater.

3. Excess Dust

Your water heater accumulates debris and dust over time. These dust and debris come from the air in your home. When you turn your water heater on after a long period, dust and debris will burn to release a strange smell. This smell can be strong enough to make you doubt the normal functioning of your water heater. You might be tempted to call the fire department; don’t. Instead, inspect the water heater to find the problem and rest easy. In most cases, this issue resolves itself, which means you do not have to do anything.

4. Gas Leaks

If you are using a gas water heater, you should check for leakages on your gas heater. Natural gas does not smell. However, water heater manufacturers add artificial smell to gas for easier detection in case of gas leakage. If you are knowledgeable about gas water heaters, you can shut the gas heater and carefully remove everyone from the house before calling the fire department. However, if you do not know how to turn it off, remove everyone from the house and call the fire department.

5. Burning Insulation

Burning insulation often results in the smell of burning rubber or burning plastic. This may occur as a result of insulation that was not packed properly or old insulation. Normally, water heaters have an outer covering of packed insulation to prevent them from becoming extremely hot for people to touch. Nonetheless, this insulation should never come in direct contact with fire. If the insulation comes to contact with fire, it will burn and produce a smell of burning rubber or plastic.

Diagnose your heater to determine if this is the main cause of the smell of burning plastic or rubber. If it is, pull the base cover off the water heater to observe the burner area.

6. Corroded Anode Rod

The water heater is made of metal, which may be corroded by water. Manufacturers fix magnesium rods in all water heaters in a bid to solve this problem. However, the magnesium rod corrodes faster than the water heater, thus releasing electrons into the tank that guards the water heater against corroding. A time comes when you will have to replace the anode rod with a new one. You will be hit with a strange smell similar to that of a rotten egg in this period.

7. Wiring Problem

If the wiring on your water heater is wrong, it can produce a burning smell. To stop this from happening, you’ll need to replace the wiring as it could be faulty. Begin by turning off the breakers that supply electricity to the water hose and get an electrician to check it out. If you need to replace it, then make sure it’s replaced and you don’t try and fix it. Faulty wiring can’t be fixed, it can only be replaced.

8. Air Pressure Problems

When there is an air pressure problem with your water heater, a smell similar to burning plastic will emanate from the heater’s location.

The vapor produced by boiling water in the heater is released through the unit’s exhaust pipes. For your water heater exhaust to work properly, the heater’s air pressure has to be used well. Failure to do this, some of the vapor produced will be left within the heater, making your home smell like burning rubber or plastic.

You can replace your traditional water heater with high-efficiency water heaters that do not have most of the issues mentioned above. Here are more benefits of using a high-efficiency water heater.

Other Smells Associated With a Hot Water Heater:

You may be getting other smells from your water heater along with the burning smell. Each smell will tell you something about the water heater. You’ll need to diagnose each problem that’s associated with the smell so that you know what the problem is.

The Water Heater Smells Like Gas

If you can smell gas, then this needs to be taken seriously as gas leaks are no joke. Try to trace exactly where the smell is coming from. If it’s coming from your gas heater, then you need to check around the hot water area. If the smell is coming from around the water heater, then it means that there’s a gas leak. Gas leaks can be fatal so you’ll need to turn off the gas as soon as you notice this. Make sure to call a gas leak company right away to fix the issue and make sure to air out the home. The professional should fix the gas leak and the water heater to prevent further leaks from occurring.

If you’re unsure of how to turn off the gas, call the fire department or do some research. Gas leaks can cause you to lose consciousness and they can even cause a fire. Any smell of gas should be taken with extreme seriousness.

The Water Heater Smells Like Rotten Eggs

If the water heater smells like rotten eggs, then it’s likely sulfur, and this smell is common with water heaters. Although it’s not common for a new water heater to give off a sulfur smell, it can happen to new water heaters. This can happen when there are high sulfur-reducing bacteria in your water supply or the anode rod is corroded. Sulfur reducing bacteria in your water heater isn’t good and you’ll need to flush and disinfect the water heater if this is the case. To prevent this smell from happening again, you should install a zinc rod rather than an anode rod. When anode rods get old, they can give off a bad smell.

Oily or Smoky Smells

If you can smell an oil or smokey smell around your water heater, then it could be the oil in the oil furnace in the water heater. Some water heaters have an oil reserve tank that injects fuel into the combustion chamber in the water heater. When the fuel is lit, this heats up a coil inside the water tank then starts to warm up the water.

These oil furnaces are typically known for their energy efficiency and they’re known to give off a smoky oily smell throughout the house from time to time. You shouldn’t be alarmed if you notice this, especially if you’ve just gotten a water heater for the first time, or you’re using it after a long period of time. But if you’re smelling this smell a while after the heater is turned off, then there could be a problem.

If you continue to smell this smell, it could be down to an oil spill or oil leak from the oil furnace, or you simply need to change the oil. If it hasn’t been changed in a while, then it can cause issues to the water heating cause it to malfunction. Oil heater also produces exhaust gases that need to be vented outside of your home. If the vents are damaged, these can cause the fumes to remain in your home which could create a bad odor and a potentially harmful one.

If you notice that the smell is there for longer than a few hours, or after the heaters have been off for a while, then you’ll need to check for leaks or try to replace the oil if it’s run out.

Musty or Moldy Smells

Over time, your water heater can produce a musty or moldy smell. This is a very common smell with water heaters, a lot more common than burning. It typically happens when the heating system has been lying around for several months and has been inactive. Once you start to use it, the smell could go away, but if it’s too strong, it may be too old and need replacing.

If the air filters are dirty or clogged, then they’ll need to be replaced. You should be maintaining your filters by filters once every 2 to 3 months. But if you use it regularly, then once per month is more appropriate. The filters are there to remove dirt, bacteria, and dust in the air. Once it becomes clogged, the heater won’t be able to do its job properly. This will result in musty and moldy air circulating your home. This isn’t ideal air to be breathing in which is why you need to turn it off and change the filters asap.


If you can smell the smell of gun powder, this could indicate that the circuit board is friend or the fan motor has suffered serious damaged. The water heater needs to be turned off and you’ll need to call a professional right away.

Benefits of Using High-Efficiency Water Heater

Fix your water heater as soon as it begins to produce a burning plastic smell because you cannot afford to miss out on the benefits of using a water heater in your home.

A water heater is beneficial in many ways. As a homeowner, you should purpose to go for an efficient water heater. This appliance does not only satisfies your hot water needs but also maximizes your home’s energy use. There are various versions of efficient water heaters in the market today. They include:

  • Demand water heaters are heaters that heat water when needed. They do not have a storage tank
  • Storage water heaters which have an insulated storage tank that is used during the process of heating water
  • Heat pump water heaters which suck heat in, from its surrounding hot air draw produced by the heater, to heat water in the storage tank

Each of these heaters uses either gas, propane, electricity, or natural gas. There are also solar-powered hot water heaters in the market that you can buy and use in your home. Here are some of the benefits of using water heaters in your home:

Lows Cost of Energy

Highly efficient water heaters (View on Amazon) consume less energy compared to the normal water heater. Most high-efficiency hot water heater models use 50% less energy. This is attributed to their ability to heat water within a short period. The tankless models heat water when necessary, thus reducing the utilization of energy. The highly efficient water heaters have also been insulated well to keep water hot for long. The solar-powered water heaters save a lot on the heater’s operation cost, up to 70% of the heater’s operational cost.

Tax Benefits

You will get tax relief or rebate when you get a highly efficient water heater. These efficient hot water heaters are some of the appliances accounted for in the federal tax incentives to promote energy efficiency. However, you need to know that the federal credits for energy efficiency are not the same across all states. These incentives allow you to get back a percentage of the high-efficiency heater acquisition cost. This tax seeks to encourage more homeowners to take part in the conservation of limited environmental resources.


Highly efficient hot water heaters do not pollute the environment like other types of water heaters in the market today. They do this by consuming less energy and emitting fewer greenhouse gases. They are also manufactured using reusable and recyclable materials, thus reducing the amount of solid waste that will end up in landfills. All these components make highly efficient water heaters your best choice.

Low Maintenance Cost

Highly efficient hot water heaters differ from traditional water heaters in that they require a low cost to maintain. They are manufactured with the latest technology to increase efficiency. Producers prioritize quality and high standards to ensure maximum efficiency when heating and supplying hot water. They require less repair and maintenance.


These water heaters are relatively small and compact compared to conventional heaters. They consume minimum space, which makes it easy to install anywhere in the house. For the tankless hot water heater, water can attain a maximum temperature at any given moment. This maximum temperature cannot be exceeded. It is set by the producer and should be considered safe for consumers. On the other hand, traditional heaters can heat water to extremely high levels because of the long heating period. This high temperature might lead to scalding.

Less Water Wastage

Like the tankless, highly efficient hot water heater, some of these models use very little water, mainly because it does not have a storage tank. It also lowers the consumption of water in your home, which leads to lower water bills. The tankless hot water heater is a good solution to use in areas where water cost is very high.


The high-efficiency hot water heaters are very durable. Most producers of these heaters provide a warranty of not less than 20 years. This is extremely good compared to traditional heaters whose warranty lasts not more than 15 years. However, they are more expensive than conventional hot water heaters. One thing though, you will get value for money when you buy high efficiency water heaters. They are made from high quality material and meet market quality standards put in place by industry regulators. You are, therefore, assured that this water heaters will last long.

This guide provides insights into hot water heaters. It takes you through why your hot water heater produces a smell like burning plastic and ways to solve this problem. Given that the hot water heater requires technical expertise to repair, you will have to call a specialist who will help you fix any problem with the heater. In case the problem is beyond repair, do not hesitate to buy a new heater, especially if the heater that you are currently using is old. When buying a new hot water heater, get a high-efficiency water heater to enjoy all the benefits listed above from cost benefits, durability, and water conservation. You will also be contributing positively to environmental conservation when using a high-efficiency hot water heater.


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