How Do You Fix A Whistling Boiler?(Top Solutions)

You may find that your boiler makes a whistling noise after using it a few times and that this problem continues to happen regardless of which brand you buy.

Boilers whistle because minerals in the water create limescale on the heat exchanger, blocking it from adequately heating the water. 

Keep reading to learn more about why exactly your boiler is making a whistling noise, how to fix it, and some tips on prevention so you can keep your boiler working correctly for longer.

Why Is My Boiler Making A High-pitched Noise?

The most common reason your boiler may begin to whistle is that there is a build-up of limescale on the heat exchanger.

A certain amount of limescale builds up over time regardless of what you do to prevent it, but it is more common for hard water places.

Hard water is in areas where there are many minerals such as calcium and magnesium in the water, even tap water after filtering.

You can use systems like water softeners and scale reducers to manage the amount of minerals in your water, but there will always be some that get through.

Another reason for the whistling could be a leak in the boiler somewhere.

Likely the leak would be in the pipework due to corrosion or over pressurization. If you have a leak in your boiler, it’s probably because the boiler itself is faulty.

Is Limescale Bad To Ingest?

One worry you may have in finding out that there is limescale building up in your boiler is whether it is terrible for you to have in your drinking and bathing water.

Limescale comes from natural elements that aren’t harmful to humans or pets, and these minerals can be good for your body and skin if you bathe in them. 

The only negative impact you are likely to experience from hard water is with your boiler, dishwater, and showerhead as the chalky substance builds up and clogs them.

How Do You Fix A Whistling Boiler?

Since there are a couple of reasons your boiler is whistling, there are a couple of ways to fix them, depending on what you are dealing with.

How To Fix A Leak In Your Boiler

A leak in your boiler is probably the most manageable problem to fix because you will most likely need to buy a new boiler.

You can avoid getting a new boiler if you want to and ask an engineer to take a closer look, but it’s quicker and cheaper to buy a new one in most instances.

How To Fix Limescale In Your Boiler

If you happen to be in one of the places in the world with hard water, then dealing with limescale is something you will routinely have to do.

Whether or not you can do this process yourself will depend on the size of your boiler and how much experience you have with repairs. When in doubt, contact a professional to help you.

The following are some steps to take that you can either try if you are comfortable or keep in mind while a professional is working on your boiler for you.

You will need to commercial limescale remover before starting the process.

To clean your boiler of limescale:

  1. Turn off the boiler.
  2. Stop any incoming water at the ball valve or other control point upstream.
  3. Remove any bath, basin, or sink plugs and open all the taps to drain the system. Close the taps once the water stops flowing out.
  4. Add the recommended amount of your limescale remover to the cold water storage tank. If you have a combi boiler that doesn’t have a tank, then you will want to remove the heat exchanger to descale it.
  5. Refill the cold water tank, so the level covers the feed connection.
  6. Turn on the boiler and leave it for four hours to heat.
  7. While waiting for it to heat, open the hot taps every fifteen minutes, so a pint of hot water comes through to help with the cleaning.

While the steps above will help clean out the limescale, the only proper way to completely clean your boiler is to recommission the system.

You will need to hire a plumber to do this properly, and you should consider flushing out the entire system regularly if you have hard water.

How To Prevent Limescale Building Up

Probably the best thing you can do regarding limescale appearing in your boiler is work on ways to prevent it altogether.

In the case of most households, you will be able to do a pretty good job of this. However, these are only ways to lessen how much limescale you will need to deal with for those with hard water.

The best ways of preventing limescale build-up are;

  • Water softeners: removes minerals with positive charges from your water. Minerals like calcium, magnesium, and sodium all have positive charges, so using a process called Ion Exchange can take these minerals out as they pass through the softeners tank.
  • Scale reducers: There are two different scale reducers that work in distinct ways. Magnetic scale reducers work like a water softener and collect the minerals before they enter the system. Electrolytic scale reducers alter the structure of the limescale, so it doesn’t stick to the inside of the pipes.

Regardless of which solution your choose to reduce the minerals in your water, you will need to find a trained engineer to install it to the overall boiler system in your home.

They may even be able to give you an idea of which option is best for your particular boiler and water system.

Final Thoughts

The biggest reason for a whistling boiler is that you have limescale. Limescale is an issue in areas with water with a high concentration of minerals like calcium and magnesium.

You can do some things to slow down the process of limescale building up, but in most cases, you will need to clean your boiler regularly to prevent blockages.