Water Heater Making Noises: Reasons and Quick Fixes


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Showering or taking a bath is one of the most relaxing ways you can do at home. But what if it turns the moment into annoyance due to noise? Worse, you're lying in your bed, and you suddenly hear strange sounds coming from the heater.

When water heaters make popping, rumbling, or sizzling noises, it's most probably due to sediment buildup. Fluctuations in water pressure, leaking, and faulty components also result in irritating sounds. If you don't flush the heater, check the valves, or clean the internal parts, you'll end up suffering from the loud noise, excessive energy, and high water bills.  

To help you troubleshoot and solve the problem, we've identified all the possible reasons why water heaters make noise. We've also rounded up DIY solutions that can even impress a plumber.

Why Your Water Heater is Making Noise?

Top Reasons For A Noisy Water Heater_

When you know how to locate and diagnose a problem, it will be easier for you to fix a noisy water heater, and subsequently, prevent it from happening again.

To make sure you'll have a quiet water heater again, let's dive first into the reasons why you may be hearing noises in the first place.

1: Sediment Buildup

The most common reason for a noisy water heater is the accumulation of sediment at the bottom of the heater. When you do not flush the heater on a regular basis, hot water bubbles form sediment.

As the mechanism heats water, steam bubbles develop underneath the sediment and explode.

Hence, the popping sounds you hear may actually be steam bubbles blowing up.

The heater will not cause an explosion in your home, but the debris can make the tank overheat.

If you let this continue, you'll end up with a noisier and weaker heater tank.

2: Accumulation of Mineral Deposits

Similar to sediment buildup, the formation of mineral deposits also produce disturbing popping sounds.

If your location has hard water, the tank will trap various materials like calcium carbonate and magnesium. Other particles like tiny stones and sand can also stay.

While such minerals cannot harm your health, they can pose a problem to water heaters. As water is heated, the minerals separate from the water.

These minerals fill the inside of the tank and its components. Limescale, which is the coating, will make the popping sounds.

3: Fluctuations in Water Pressure

Have you ever woken up to the sound of a water heater making ticking sounds? More often than not, it's because of fluctuations in water pressure.

When water pressure from the street fluctuates, the air cushions become waterlogged, which sometimes also results in hammering noise.

While an external factor mainly causes this one, the effect can be damaging to the water tank.

4: Household Plumbing

If your water heater is making ticking sounds, it's because of loose pipe straps that hold the hot water lines.

When cold and warm water passes through pipes, they change the tube's diameter.

As pipes expand and contract, they hit the frames and straps, resulting in ticking noises.

5: Leaking and Condensation

Leakage can often make a water heater noisy. First, look for the spot with a puddle.

When water droplets form in the tank, they can land on the unit's burner. Once you turn on the heater, it will make a sizzling sound.

6: Poor Water Flow and Valve Issue

Whenever you hear knocking or hammering noise, it often indicates the restriction of water flow.

Most plumbing systems have built-in measures, like air cushioning devices, that can control this situation.

If the relief valve is fully closed, the heater may also make sizzling sounds. This is due to the water not flowing in the tank with ease.  

If you hear a sizzling sound from your heater, this means that water does not flow into its tank with ease. You can trace this problem to some valves in the unit.

7: Faulty Heating Element

There's a heating element on the top and bottom parts of the heater. Note that it's normal for the upper heating element to vibrate.

When cold water enters the tank and moves around the unit, the heater's top part will shake and produce humming or crackling sounds. 

If you hear popping sounds in the water heater, it's also possible that the sediment buildup at the bottom of the tank has buried the lower heating element.

8: High pH Level

If your water supply has a high pH level, and the heater's anode rod is made of aluminum, a reaction called aluminum hydroxide may happen.

This is a common issue in areas that have chloramines or chlorine in the water supply, especially since chlorine has a pH level of 11.7. When the reaction occurs, a gel-like substance forms at the bottom of the tank and/or the anode rod.

9: Dirty Water Heater

Another common reason why water heaters are making noises is because of accumulated dirt over time. When the heater makes hot water, the liquid expands and passes through the debris.

As a result, you can hear rumbling, hissing, or cracking sounds as the water moves through the dirt.

This implies that there's a large amount of dirt in the heater. While this is not harmful to you, it can impact the performance of the heater.

How to Fix a Water Heater Making Noises

After learning why your water heater is haunting you with popping, sizzling, or crackling sounds, the next part is learning how to solve this by yourself.

From flushing to replacing components, you can make your unit quieter in no time. Here are step-by-step guides on how to make a noisy water heater quieter.

1: Drain and Flush the Water Heater to Prevent Sediment Buildup

Flushing a water heater out not only solves sediment buildup issues but also prevents it from happening ever again.

To make sure you are flushing the heater correctly, follow these simple steps:

  • If you have an electric water heater, turn off the device at the circuit breaker. If you're using a gas water heater, turn the gas switch to pilot.
  • Turn the cold water supply lever to a 90-degree angle to stop water from entering the water heater.
  • Link a garden hose to the drain valve.
  • Put the other end of the hose in an area where you can drain the hot water. If you can't put the other end of the hose outside, use a basin to catch the water.
  • Open the pressure relief valve and open a hot water spigot in the house to enable water to come out of the hose.
  • Open the drain valve to allow dirty water to come out. Be careful as the water is most likely hot.
  • After draining the water, only then can you perform the "flushing".
  • If you've opened the pressure relief valve, close it before turning on the cold water supply.
  • Turn the cold water supply lever on the open and shut positions a few times to flush out the remaining sediment in the tank.
  • Do this until you see clear water.
  • Close the drain valve and unlink the hose from the valve.
  • Turn the cold water supply lever back in line with the cold water inlet pipe.
  • Wait for 10 to 15 minutes for the water heater to fill back up.
  • Turn on a hot water faucet to purge any air out of the tank.
  • Turn the heater on again to begin heating the water.

Remember, flushing your water heater as often as possible can help you avoid dirt and sediment buildup.

If you delay this task, it might make flushing difficult as the amount of residue thickens. When this happens, the tank can deteriorate and prompt a leak.

2: Put on a Water Softener

When you install a water softener, you can stop the formation of sediment buildup, and consequently, popping noises.

If you choose to ignore sediment buildup, it can result in rust and leaking, leading you with the only choice to buy a new heater.

With a water softener, you can remove the sediment that forms in the tank. It is a type of filtering device that removes magnesium and calcium in the water.

A water softener comes in three varieties:

  • Salt-free: This type of water softener optimizes mechanical filters to get rid of calcium. While it does remove magnesium, it may not work very well on hard water.
  • Ion exchange: This is the most common type of water softener for home heaters. It removes magnesium ions and calcium by replacing them with sodium ions.
  • Reverse osmosis: This type filters water through a semipermeable membrane that takes away as much as 98% of water impurities. However, it uses a considerable amount of water, making it an expensive device.

3: Inspect the Plumbing System

A simple way to stop a water heater from making noises is by checking the pipes and decreasing the pressure or lower the temperature on the water heater. By doing so, you reduce the pressure and noise at the same time.

Aside from that, you can try to locate where the sounds are the loudest. In this way, you can secure the pipe tightly or install spacers to prevent the pipes from moving.

Furthermore, you can turn off the water supply and open up all of the faucets to let the air cushions fill back up.

4: Install a New Heat Trap

In a trapless system, the inlet pipes expand and rise as the unit heats the water inside the tank.

A heat trap allows the unit to prevent heat from dissipating through the plumbing, even on standby mode.

Turn on the hot water tap to lift the balls or flaps and enable an unobstructed flow.

The old designs of heat traps consist of a pipe formed as a valve or loop. These have the ability to store heat and make heaters work better.

For new models, heat traps are incorporating small metal elements called "nipples", which are small pieces of piping.

Due to the heat traps' position on the water inlet and outlet pipes, the nipples prevent heat from escaping despite convection.

If you want to say goodbye to ticking sounds, make sure to inspect if the nipples with heat traps are working properly.

5: Check the Valves

To stop a water heater from making sizzling sounds, check the temperature and pressure relief valve first.

This device releases water from the storage tank, especially if there's too much pressure.

Once you hear disturbing noises from the relief valve, turn off the power switch and water supply.

Moreover, it's possible that there are closed valves or bent lines. Thus, inspect if the water inlet valve is fully opened.

This is the water valve on top of the heater that lets incoming water enter the water heater.

6: Delime the Tank

Unless you have a soft water system, liquefied limestone will create a layer of rocks on the bottom of your water heater.

Aside from flushing, deliming the tank helps remove residue in the tank. In addition, this process requires you to replace the anode rod with a model made with magnesium.

And it will be worth it. So let's begin by learning how to delime a water heater tank:

  • Turn off the power to the water heater.
  • Pull the pressure regulator lever up to release the pressure inside the heater.
  • Use an adjustable wrench to remove the pressure regulator.
  • Open up the drain valve and allow water to drain. Drain the water heater from the drain valve.
  • Close the tank after draining.
  • Use a funnel to pour in a gallon of vinegar or descaler solution through the pressure relief valve hole.
  • Let the solution sit for about 20 minutes.
  • Turn the main water valve on and fill the tank to about halfway, then drain again.
  • You should see foamy and milky water. If there is still a presence of limescale, repeat the descaling process.
  • Fill and drain the tank two to three times to purge any leftover solution.
  • Close the valve and reinstall the pressure relief valve.
  • Use plumbers pipe thread compound to coat the threads.
  • Use an adjustable wrench to screw the valve tightly.
  • Fill the water heater and turn the power back on.

7: Clean or Replace the Heating Element

Heating elements are also known as immersion heaters because they are fully submerged in the water of the tank.

As the sediment forms in the tank, it will settle at the bottom where the lower heating element is found. In effect, the sediment surrounds the element, causing it to lose effectiveness while also making vibrating noises.

When this happens, you should drain the tank first before removing the heating element.

Soak the heating element in vinegar and use a wire brush to clean it. If it's beyond cleaning, that's a sign for you to buy a new heating element.

8: Use a Leak Detector

Some people choose to wait until their tanks start to leak before doing anything. If you still want to do this, it's advisable that you install a water heater leak detector.

With the help of a leak detector, you can identify a leaky tank. This type of alarm helps prevent a huge mess by alerting you when the sensors detect water leaking from the tank.

9: Replace the Water Heater

If you've tried everything and nothing worked, maybe it's high time for you to replace the water heater. Newer models typically last for six to 10 years.

So, if you know that your unit is nearing its threshold, consider purchasing a new one.

  • The good news is that you can install a water heater by yourself.
  • Shut off the water supply to the water heater and electrical power.
  • Open the valve to drain the water.
  • Once the tank is empty, disconnect the flue pipe and lines for water, gas, and electricity.
  • Clean up the area for the new water heater.
  • Set the new unit in place and reconnect all necessary lines.
  • Refill the water tank and set it to the temperature you want.

10: Clean Your Water Heater

Whether you're using an old or new water heater, there will be times when it will surprise you with noise.

The best way to stop it is by cleaning your water heater occasionally. Remember, letting residue live inside the tank can lead to extra costs in replacements or repairs. 

The cleaning usually involves flushing, which you learned earlier. Another way is to add vinegar to your hot water tank, which should aid in breaking up the deposits or any type of debris.

Maintenance is an excellent way to guarantee that not only ensures your water heater remains clean, but also you get to use water and energy efficiently.

When Should I Call a Plumber?

As mentioned earlier, checking the valves might not work best if you don't know what you're looking for. This is where professionals can take over.

If you don't have the equipment to install a new heat tap or put on a water softener, that's also when it's fitting to seek a plumber's assistance.

Final Thoughts

When your water heater is making noises, it usually indicates a problem. Therefore, it's important that you locate and identify the issue first. In that way, you can apply the appropriate solution.

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