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My Water Heater is Making Strange Sounds….. Why Is My Water Heater Making Noise? 

If your water heater is making noise, it can be from a list of items depending on if you have a gas water heater, an electric water heater or tankless. Let’s cover some of the basic concerns and reasons why your water heater is making noise. 

Sediment

The first thing that jumps to mind when a client says their water heater is making noise is that they have sediment build up. Sediment buildup is incredibly common in Phoenix due to our hard water that is full of minerals.  When you have hard water those minerals in the water like to stick to everything! If you have noticed the mineral build up on your faucets then you know exactly what I am talking about, and that is another subject all to its own. We have written on that as well and can be seen here. 

How is sediment making noise? 

When sediment is the cause of the noise at your water heater it is because the minerals are sticking to components. These minerals not only stick to the components in your water heater they also build up inside the tank. The most common scenario is in electric tank style water heaters. The heating elements inside your water heater can attract the minerals to them as they cool down, especially if your anode rod is in poor shape or gone.  The minerals can also adhere to the side of the tank as well.

After the element has cooled down and attracted the minerals to stick it, eventually the water needs to be heated again and the element will be turned back on to do so. As the element heats up and both the element and tank expand from the thermal expansion the minerals that have collected on the element may crack and break off of the heating element. When this happens, it will make a popping or cracking sound. As the flakes of minerals/sediment pop off they sink to the bottom of the tank and build up. This leads to the second way sediment can cause noise. 

Sediment buildup

Although sediment build up is more common in electric tank style water heaters, it does happen in gas tank style water heaters too. When you have sediment build up in the bottom of the tank it can break and shift. The breaking and shifting makes a similar popping sound. Sediment buildup in the bottom of your water heater can also cause your water heater to work harder to keep up with demand. This build up of sediment can drastically reduce the gallon capacity of your water heater. This reduction in gallon capacity forces the water heater to work harder to keep up with demand.  Sediment takes up space, that used space from sediment means less storage space for hot water.  

Other causes for noise at your water heater

Some other things that can cause a noise coming from your water heater can be old elements. As the heating elements in your electric water heater get older than can become loud just running. When this is the case it will usually sound like a hissing sound or white noise. A common noise coming from gas tank style water heaters is the expansion and contraction of the tank and or the flu baffle. What is a flu baffle you ask? The tank for a gas water heater has a tube running through the center of it called a flu. The flu allows for the exhaust gasses to move through and exit through the vent at the top of the water heater.

In order to take advantage of this hot exhaust there is a baffle. The baffle is basically a strip of steel twisted into a spiral to slow down the exhaust a bit allowing for some of the heat to be absorbed into the tank helping to heat the water. As the tank and/or the flu baffle heat up they can expand and make a noise while doing so. Heat trap nipples can also be a cause for sound at your water heater.  Heat trap nipples aren’t as common anymore but if you hear a rattling sounds it’s worth checking to see if the heat trap nipples on your water heater need to be replaced if you have them.  

Causes of Sounds at your Water Heater that aren’t caused from your water heater.  

There are other external causes for noises at the water heater as well but these are case by case basis and require diagnosing.  Not every home has these options on their water heater as they optional upgrades such as recirculation pumps for example. Mixing valves and booster pumps are also an upgrade option that could be causing noise at your water heater.  When booster pumps and mixing valves require repair or replacement they can make noises you’re not accustomed to hearing. Another cause of noise at your water heater could be a water hammer. A water hammer may have nothing to do with your water heater at all. That’s just where the noise traveled to. If you’re concerned about noises at your water heater and you want to go to the bottom of it Call a Robin, we’ll figure out the cause of the noise and provide you with options to take of the issue.

Services in Phoenix & Beyond

When you’ve found yourself in need of water heater repairs or installations or 24-hour plumbing services in the Phoenix, Glendale, Scottsdale, or Chandler area, you can trust Robins Plumbing. We will provide you with prompt and expert care!  Contact our team today! In addition to our slab leak repairs, we also offer a variety of residential and commercial plumbing services, including: drain cleaning, water heater repair and replacement, sewer camera inspection and locating, backflow prevention, commercial and residential jetting, water treatments, and more. Visit our reviews online to see what others have to say about our local plumbing company!