Is Your Water Heater Making a Knocking Noise? Here’s What’s Happening

Water heaters work best when they are out of sight and out of mind. So, if you start to hear a strange knocking noise coming from your water heater, you’re right to be concerned. Knocking sounds can point to a range of issues with your water heater that will need to be addressed before the problem worsens. Fortunately, our team at Dean’s Home Services knows all about water heater problems, so we’ve put together this guide to cover the common causes and solutions to a knocking noise from your water heater.

Four Causes of a Knocking Water Heater

Water heaters are complex systems with various parts and components. Because of this, there can be a range of reasons behind the strange noises from your water heater, such as:

1. Sediment Buildup

Over time, minerals in your water will start to settle at the bottom of your water heater tank, especially if you have hard water, which much of the Twin Cities does. As water heats up in the tank, steam will need to rise through this sediment. As the steam builds up, it will force its way through the sediment. When this happens, you’ll likely hear a sound akin to knocking or popping.

2. Water Hammer

While a water hammer may sound like something a superhero has, it actually refers to water flow suddenly stopping or changing direction, often due to a change in pressure. When this happens, the shockwave can cause pipes and water heaters to shake and rattle, which could be the source of the knocking sound.

3. Loose Components

From the heating elements and anode rod to the dip tube, your water heater has many parts. If any of these parts come loose, they can start to rattle around your water heater when it’s in use, which, in turn, could sound like knocking noises.

4. Thermal Expansion

When things get hot, they expand, and when they get cold, they shrink. This is known as thermal expansion and is something your water heater experiences often as it heats up water for your use. The expansion of the tank and the surrounding pipes can make a knocking sound.

Troubleshooting Your Water Heater

If your water heater is making concerning knocking sounds, it’s time to try troubleshooting the issue. Because sediment buildup is the most common cause of a knocking sound, you should try flushing the water heater first. Flushing the tank will remove the sediment buildup, which should address the knocking sounds.

To do so, turn off the power supply to the water heater and wait for the water to cool down. Then, connect a hose to the drain valve and direct it to a safe drainage area or a large bucket to contain the water. You can then open the valve until all the sediment and water have drained out. Once you’re done, you’ll need to close the valve, refill the tank, and restart the water heater.

If this doesn’t solve the issue, conduct a visual inspection of your water heater to look for any loose parts. Try tightening any components that have come loose and see if that fixes the knocking sounds.

Call Dean’s for Professional Plumbing Repairs

If the above steps don’t fix the issue, it’s time to call in the professionals. Attempting any further DIY repairs can be unsafe and lead to further damage to your water heater. Professional plumbers have the skills, tools, and experience to get to the root of the issue and perform the needed repairs.

At Dean’s Home Services, we have extensive experience repairing all kinds of water heater issues. We’ll diagnose your water heater problem and fix it quickly so that you can get back to enjoying hot water without the annoyance of any knocking noises.

Call Dean’s today to schedule water heater repairs in Minneapolis, St. Paul, or the surrounding areas.