You turn on your dishwasher or run hot water from a faucet and within a few minutes, you begin to hear a loud whistling noise. As you follow the sound you discover that it’s coming from your water heater.

So, why is your water heater whistling and how do you stop it?

First thing to know is not to panic, it’s not going to explode. BUT – it does mean that something is wrong and as with any other plumbing problem – the longer you wait – the more expensive the fix could be so we do recommend that you get it checked and fixed as soon as possible.

In order to stop that noise you do need to find out exactly what is causing that noise – truth is – it could be several different issues.

Why Is My Water Heater Making A High Pitched Noise?

The reasons that you’re hearing that high pitched noise (even if it’s just a few minutes) are…

  • A problem with your Temperature Pressure Relief (TPR) valve.
  • A problem with a loose drain valve.
  • A problem with the cold water inlet / hot water outlet.
  • There is a crack in the water heater tank.

You’ll have to try each one of these to find out what is causing the issue so let’s go over these steps in detail.

We do recommend that you contact a plumber to fix these following problems.

Cracked Water Heater Tank

The first thing to check (because it should be the easiest) is to find out if the water heater tank is cracked. The signs to look out for are…

  • When you run your hot water from a faucet – it’s a rusty brown color.
  • You hear alot of rumbling noises coming from your water heater.
  • You don’t have enough hot water (which you can usually tell when you are taking a shower).
  • Your water heater is old.
  • You see water at the base of the water heater tank.

If you can say “yes” to any of these situations in your home then you most likely have a crack in your water heater unit.

The solution is to replace that unit with a newer one.

We recommend that you contact a professional plumber for this task.

Problems With The Temperature Pressure Relief (TPR) Valve

This is a very common issue (even with new water heaters) and it can certainly create not only that loud whistling noise but also the sound of banging pipes as well.

The purpose of this valve is to act as a safety feature to prevent too much pressure building up in the tank. It essentially releases the pressure from the tank and should only begin working when the pressure builds up to a hazardous level.

It’s very normal for hot water heaters to create steam and build up pressure during daily use – but if that pressure reaches a certain level, the TPR valve is there to protect it.

The solution here is to replace the TPR valve.

Loose Drain Valve

After some time, a leaky hot water heater can also deteriorate the drain valve, which may then need to be replaced.

The drain valve is normally located near the bottom of the tank and it should always be completely closed. If it’s leaking the solution could be as easy as replacing a worn out washer that is causing a problem with it but you may also have to replace the valve itself.

Cold Water Inlet / Hot Water Outlet Problems

If you can get close enough to your hot water heater- you may be able to identify if that whistling sound is coming from the top of the unit. This is where the cold water inlet / hot water oultet is located.

If you DO hear that high pitched sound coming from there (which is very common by the way – especially on older water heater units) then the solution is to have that component replaced.

Again, a plumber can come in and fix this problem for you as well as any other issues that may be causing that very annoying whistling sound.

If you have any questions about water heaters or are having some problems with it, call Atlantis Plumbing today at 770-505-8570. We are available 24 hours a day, 7 days a week.