Why Does My Water Heater Whistle?


Hearing sounds coming from your water heater might feel alarming, but it actually is not out of the ordinary.  In fact, it is actually common for your water to make noise – it does not automatically mean that something is wrong.  You might hear banging or rumbling, crackling and hissing, ticking, or popping.  For example, hearing the occasional crackling or hissing sounds is perfectly normal in moderation.

If your water heater begins whistling, it does not necessarily mean that something detrimental is wrong with the structure.  However, it can signify that something needs attention.

If your water heater has started making a whistling noise when it never did before, it is not a bad idea to have it checked out.  Keep reading to learn more about what may be causing the water heater to make a whistling sound.

What Causes Water Heater Whistling?

There are many reasons why your water heater is whistling.  Rather than ignoring the issue, you may want to address it before a larger problem occurs.  The following are a few of the reasons why your water heater might have suddenly started whistling.

The Tank Has Cracked

Since you likely do not look at your water heater all the time, it is not uncommon for it to develop a crack without you realizing it.  If your water heater does have a crack in it, it will most likely start whistling.  This whistle is a result of air escaping or entering the tank itself.  Unfortunately, if your water heater tank has cracked, you are more than likely going to need to replace it.

Worn Out Inlet and Outlet Connections

There are two connections on your water heater – the inlet and the outlet. These connections will wear out over time.  One connection lets the cold water in, while the other lets hot water out.  The hot water connection is more likely to be the one to wear out first.  Regardless of which connection has started to wear out, you will likely hear a whistling sound as a result.

Loose Drain Valve

Over time, sediment is likely to gather at the bottom of your water heater.  These sediments may include things such as sand and grit, which usually come from municipal water lines.  The purpose of the drain valve is to allow you to drain those sediments from the tank.  If the sediments are not drained, your tank may not function quite as well as it did before.

However, the sediment is not what will cause that whistling sound to come from your water heater.  If the drain valve gets loose, it will actually create a whistling sound similar to that of a worn inlet or outlet connection.  The air is able to escape in or out while the drain valve is loose.

Keep in mind that to increase the functionality of your water heater, you will want to drain the sediment at least once a year.

It’s Just The TPR Valve

Your water heater has a valve called the temperature pressure relief valve – and it’s job is exactly what it sounds like.  The TPR valve will open up and allow pressure to escape the tank.  This happens when there is too much buildup within the unit.

Typically, you do not hear the TPR valve because it does not need to kick in unless the pressure has reached a dangerous level.  However, when it does happen, you are likely to hear a whistling sound coming from your water heater.  This just means that the TPR valve is doing its job and is keeping the pressure within the designated safe levels.

Is Water Heater Whistling Dangerous?

The whistling sound coming from your water heater may seem a little scary.  But is it dangerous?  In short, no, a whistling water heater is not necessarily dangerous.  However, it does signal that something is almost definitely wrong with the water heater.  If you have checked to make sure all of the connections are secure and there are no cracks in the tank, it may be best to contact a trained professional.  

A water heater whistling is not exactly a normal noise if it is functioning properly.  You want to make sure that you solve the issue with the water heater before it turns into a bigger and more problem.

Contact White’s Plumbing Today

Do you have a water heater that has suddenly started whistling near the Sanford, North Carolina area?  If so, consider contacting White’s Plumbing!  Our certified technicians have years of experience handling issues with water heaters.  Once we take a look at your water heater, we will be able to diagnose and solve the problem in no time.  If you have an emergency with your water heater, we offer a fifteen minute response time on our emergency line.

Contact us today by filling out the form on this page or by giving us a call.  Someone will be in touch with you shortly to figure out the most convenient time for you to have a technician stop by your home.  We look forward to helping you soon!

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