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Heating, Cooling, Wine Cellars | Birmingham, AL


Everything You Need to Know About Water Hammer

No, water hammer isn’t a special move in a video game — it’s a unique problem that can occur to residential-sized boilers, causing them to make a loud and uncomfortable noise. We understand that boilers can be some of the most reliable and long-lasting heating systems in existence, but that doesn’t mean they can’t develop problems like water hammer.

That being said, there is only one solution to a problem like this and that’s professional boiler repair. That’s because a problem like water hammer is caused by pressure, temperature, and a malfunctioning boiler. In order to avoid any confusion when signing up for boiler repair, it’s good to know what water hammer is and how it is caused. Steam heating systems are popular in our area, and it’s generally a good idea to have a little bit of background knowledge for an accurate description to an HVAC professional.

So, let’s get into it!

What Is Water Hammer?

Also known as hydraulic shock, water hammer is when the water in your boiler or pipe system suddenly changes direction. This can cause a loud banging noise as the pipes resonate, expand and contract, as well as strike against their wooden frames. Now, if you don’t remember anything from your high school chemistry class, then we understand how someone might not understand how this can happen. After all, water in the ocean or in a lake doesn’t suddenly change direction, right?

Well, when you mix heat into the equation (like our boilers do every day), and water begins to evaporate and change forms, there can be strange physical events that happen.

Causes of Water Hammer

So, now that we know water hammer is when water suddenly or rapidly changes direction and pressure, we can more easily pinpoint the cause of it. Here are a few examples of how water hammer can happen.

  • Your boiler is overfired. This can happen if either you’ve got a boiler that’s too large for your piping system (i.e. from a bad replacement) or you’ve got some other problem with your gas burner that’s causing the temperature to rise too high, too quickly. By overfiring your boiler, water will surge violently and sometimes be jetted into pipes, causing a loud hydraulic shock.
  • Loose pipes. While this has less to do with your boiler and more to do with your piping system, loose pipes can contribute to water hammer because they’re easier to shake. Your pipes have to be secure enough to handle a mild amount of pressure, heat, and steam. If they’re secured too loosely, they’ll bang against one another.
  • Not enough room for condensate. Usually, when your boiler produces steam to heat your home, any condensate is supposed to drain back into the boiler via gravity. However, if your pipes are the wrong size or have the wrong pitch (or slope), the water will get stuck in your pipe and you’ll hear water hammer as it is constantly jetted violently by the incoming steam.

The good news is, none of these problems are particularly catastrophic or dangerous. If you suspect one of these is the culprit, then there are simple solutions that can be achieved by a professional.

Call our boiler professionals here at Sullivan Service Co to have peace of mind and to join the Comfort Zone!

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