How to Repair a Creaking Noise in a Water Heating and Plumbing System - DIY Troubleshooting Tips

If you are one of many homeowners with a water tank heater making a creaking or squeaking noise and wondering if a noisy water heater is dangerous, if you can fix it, and how, you have come to the right place.

Whether you have to deal with mineral deposits, poor water flow, fluctuating pressure, or leaks, this article will help you find the cause of that unusual sound and show you how to repair it.

A noisy water heater is not something you want to deal with daily, especially if it sounds like a train or jet engine and is located in the house.

Note: Every water heater makes some noise, but if it is inconsistent and sounds like popping, banging, knocking, rumbling, and screeching, you might have a problem, so check out this article for the repair tips.

Thermal expansion as the cause of the creaking noise

The main reason for the creaking noise in water heating and plumbing systems is thermal expansion when the unit operates with higher temperatures.

Thermal expansion occurs when the temperature and pressure inside the tank increase, making the tank stretch, and when the pressure is relieved, the metal tank "shrinks," returning to its original shape. This process of expansion and contraction could often lead to unusual sounds, even deformations.

Also, if the water pipes are too tightly secured to the wall and as they cannot expand when hot water is running though, increased friction between the pipes, mounts, and studs would generate the creaking noise. Replacing metal clamps with plastic ones could reduce the noise.

If your pipes are exposed to colder air, such as when running through the basement or garage, expansion, contraction, and rapid temperature in the pipes can be reduced by adding insulation to your pipes. This will keep them at a consistent temperature and silent.

Reduced water flow as the cause of the creaking noise

A water pipe can also make a creaking noise when the heater is recovering, and all the valves are closed. These valves include the check valves used to prevent mixing the potable residential water with the municipality water system, pressure reducing valves used to conserve water, and a water softener that acts as the back-flow valve.

If you are not sure about the thermal expansion and if the pressure increases over the recommended maximum, follow these steps to test it (it applies to the closed system only):

• Put the thermostat setting to the lowest position.
• Install the water pressure gauge on the drain valve, which you should open for testing.
• Open the hot water tap and drain approximately 20% of the tank volume.
• Shut off the drain valve. Turn off all the fixtures in your home.
• Allow the water heater to cycle by increasing the temperature on the thermostat.
• As the water temperature inside the heater’s tank increases, the pressure will increase too rapidly. If the pressure exceeds the maximum setting on the PRV or TPR valves, the valve should open and release the water. Also, valves will close once the pressure drops below its maximum setting.

Note: Extreme temperature and pressure inside the tank can lead to deformations and leaks, which is expensive to repair.

Expansion tank as a solution?

In order to avoid high water pressures and protect the heating system from the creaking noise and deformations, both the PRV and thermal expansion tank should be installed. The benefits of having the pressure relief valve installed are saving water, prolonging the life of water flow valves, and allowing the selection of an economically-priced expansion tank.

The most used expansion tank is the tank that has two chambers and one flexible membrane in between. One chamber is filled with water, the other with air, so there is always room in the air chamber to compensate for the increase when there is water expansion. When this device is installed, and the pressure starts to climb, there will only be a slight pressure increase to a point where it will stay and keep the steady pressure.

Other sounds you can also hear and possible causes

In order to avoid dangerous situations with your faulty water heater, pay attention if the unit starts suddenly making weird noises. Some of the common sounds are listed below, including the most typical causes.

Popping sound. If you live in an area with hard water, mineral deposits and debris can easily accumulate at the bottom of the tank. The sediment buildup may trap hot water and steam bubbles underneath, resulting in the popping sound when trying to escape through the layer of sediment buildup.

The solution for this problem is to flush the system using the drain valve, as described here.

Crackling sound. A crackling sound can often be found in high efficient gas water heaters, and it occurs during condensation or moisture buildup, when the water droplets are vaporizing when in contact with the burner.

It can also mean that water is trying to go through the sediment layers.

Sizzling sound. A sizzling sound is a sound of water dripping on the hot surface. If it happens due to condensation, there is not much you can do - just wait until it disappears, but if the root cause is the leak, then you might want to call a professional to check.

Banging sound. Banging sound often occurs when there is a sudden pressure change in the system, such as when water entering or leaving the tank is rapidly turned off. This is also known as a water hammer and is causing pipes to bang against each other or nearby studs and walls. In order to prevent further noise and damages, it is recommended to install a water hammer arrestor and anchor the pipes securely.

Conclusion

As we can see, it is common for your water heater to make some noise while running, especially when it has to work harder.

In general, water heater sounds, such as creaking or squeaking, are not dangerous but do require some attention. Sometimes regular maintenance such as draining/flushing can prevent or stop the noise, so make sure to inspect the unit as recommended.

If you are concerned about a water heater noise and not comfortable working on it, contact a professional for assistance.

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