Why Is Your Boiler Making Banging Noises in Mequon, WI?

Professional Services
March 10, 2025

If you have a boiler making banging noises, you need to schedule boiler repair services in Mequon, WI, as soon as possible. Banging noises in a boiler are a sign of serious issues that could be dangerous if you leave them unattended.



If your boiler makes this persistent sound, it could be due to several issues that could compromise the tank’s structural integrity. Put an end to this and other boiler issues by contacting Professional Services to diagnose and fix them.


Five Common Reasons Your Boiler Is Making Banging Noises

Boilers typically make some noise during normal operation, such as a quiet humming noise from the circulating pump or periodic clicking or rushing sounds as the system turns on. However, loud banging noises on the inside of the boiler tank and pipes are not normal and could be a sign of several issues. 


1. Boiler Kettling

Boiler kettling is the name for a phenomenon that occurs when there is excessive limescale buildup in the tank. Hard water can deposit limescale on the bottom and sides of the tank, which restricts water flow, causing it to turn to steam. This process results in a low rumbling noise and sometimes a high-pitched whistling as the water starts to boil, and there is air in system components, almost like a tea kettle. 


Boiler kettling is especially dangerous when sediment layers cover the heating element. The sediment blocks heat and traps a layer of water that consequently becomes superheated and vaporizes, flinging sediment against the sides of the boiler to make a constant pinging noise. You can prevent boiler kettling and overheating by draining the tank and flushing sediment from the system.


2. Water Hammer

A water hammer is another common reason a boiler makes banging noises that distract your entire household in Mequon. The term water hammer refers to the sound produced when water quickly reverses direction in a pipe, creating a loud smashing sound like a hammer behind the walls. This issue primarily occurs due to boiler pipes having incorrect pitch or pressure issues. 


3. Delayed Combustion

If you have a gas boiler, any loud banging noise could be due to delayed combustion. If your boiler's ignition sequence takes too long, gas might build up and suddenly ignite, creating a loud banging sound on start-up. Even though the explosion is small, it is still powerful enough to damage your boiler pipes after repeated exposure. 


4. Thermal Expansion

In some cases, banging noises are due to the thermal expansion of boiler components. Most boilers have metal components that expand and contract from heating and cooling.


If metals expand or contract quickly, they can produce pinging and banging sounds that reverberate through pipes and into radiators. A small amount of thermal expansion is normal, but excessive expansion can prematurely wear pipes and components. 


5. Loose Components

Another cause of a boiler making banging noises is loose components and connectors. System activity can cause components to vibrate, producing a distinct buzzing or rattling sound as they move around. Loose components might make scraping sounds as they move against other parts, which can cause serious damage. 


How Long Do Boilers in Mequon, Wisconsin, Last?

Boilers typically last about 10 to 20 years, depending on the model and use conditions. However, cold weather can significantly affect a boiler’s lifespan due to the negative consequences of freezing water.


Mequon’s winter temperatures easily sink below freezing, meaning that the harsh winters can drastically affect boiler lifespan. If you don’t get regular maintenance, your boiler can start showing signs of aging within a few short years, especially if you have an older tank boiler. 

The best method to keep your boiler in good condition is by scheduling regular maintenance services. Don't hesitate to contact a professional in Mequon if you start to hear frequent banging sounds.


In extreme cases, the cause of the noise could cause an explosion or, at the very least, damage the tank beyond repair. Scheduling preventative maintenance now is a better option than prematurely having to buy a new one in the future. 

Professional Services Today for Boiler Repair

Contact Professional Services Today for Boiler Repair and Maintenance in Mequon, Wisconsin

Professional Services is Mequon's trusted HVAC company for all your boiler needs. If you would like to understand the industry's boiler and furnaces comparison or have a boiler making banging noises that needs immediate repair, contact us online or call today! We’re on call 24/7, so you can reach out to us at any time!

You might also like

July 25, 2025
Can you plug an AC into an extension cord? Call Professional Services 24/7 for emergency help so you don't risk a fire using the extension cord.
July 25, 2025
Can a bad AC compressor cause overheating? Let's find out how low refrigerant levels, dirty condenser coils, and other problems contribute to overheating.
July 25, 2025
Why does my AC compressor shut off after 2-3 minutes? Find out how electrical problems or thermostat issues might cause the problem in Thiensville, WI.

Book a Service Today