Why is my boiler making noises? July 09, 2025 Boiler noises can be unsettling, especially if you're used to a relatively quiet heating system. Whether it’s a gentle hum or a loud bang, unfamiliar sounds are often your boiler’s way of telling you something isn't right. Addressing these noises early can prevent costly repairs or even full replacements. Common Causes Behind Noisy Boilers and What to Do About Them Kettling and Gurgling Sounds A common cause of banging or boiling noises is limescale buildup in the heat exchanger. This is often referred to as kettling and is particularly common in hard water areas. The build-up restricts water flow, causing overheating and steam formation. A professional powerflush or descaling treatment is usually required. Banging or Clunking on Startup This may point to issues with ignition or trapped air in the system. If it's the ignition, your boiler might be attempting to fire but failing due to gas supply issues, faulty components, or blocked burners. Trapped air, on the other hand, can cause sudden pressure changes. Bleeding your radiators may help, but a heating engineer should check the gas-related components for safety. Whistling or Hissing This can often be linked to low water pressure or air trapped in the pipes. It might also mean the pressure relief valve is faulty or leaking. Check your boiler’s pressure gauge, it should typically sit between 1 and 1.5 bar when the system is cold. Vibrating or Humming Noises These tend to be linked to loose components such as brackets, pump bearings, or fan blades. Although not usually an emergency, they should be investigated to prevent further wear or component failure. When to call a professional heating engineer While some noises can be resolved by bleeding radiators or repressurising the system, others require a trained eye. Persistent or worsening sounds could indicate worn parts, sediment build-up, or more serious safety issues. A qualified gas or heating engineer in Wolverhampton, Walsall, or Cannock can carry out a full inspection and advise on any repairs needed. Preventing Future Boiler Noises Regular servicing keeps internal parts clean and efficient Installing a magnetic filter helps trap debris in the system Using water softeners or inhibitors can reduce limescale formation Annual system flushing may be recommended if sludge buildup is recurring Need a boiler check in Wolverhampton, Walsall, or Cannock? HeatFire offers boiler repairs to keep your home warm and your heating system running quietly. Call us today or fill out our contact form to book your visit. Whether it's a noisy boiler or time for a new installation, we're ready to help across Wolverhampton, Walsall, and Cannock.
