G&C Plumbing and Heating
My Boiler is Making Noises it Didn't Make Last Year
Updated: Sep 27, 2022

Boilers should be seen and not heard.
When something's wrong with your gas boiler, you'll probably hear about it. A noisy boiler is one of the most obvious (and annoying) warning signs that your heating system is in need of repair or replacement.
The first step is to determine why your boiler has suddenly started making these strange sounds—and the answer to that usually lies in the type of noise it's making:
Whistling
If your boiler is making a whistling noise that reminds you of a hot kettle on the stove, that's a sign that air might be trapped within the system. The solution is often as simple as releasing the air, and finding out what trapped the air in the first place.
Gurgling
If your boiler is making gurgling sounds, there might be blockages at the bottom of the boiler, low water pressure, or trapped air. If the weather's cold, it might even be a frozen condensate pipe that will need to be thawed before proper functionality can be restored.
Banging or clunking
If your boiler is making a banging noise or clunking sounds, there might be a buildup of limescale from hard water or debris from corrosion in the system, which might be blocking the safe travel of water. This is known as "kettling." Left untreated, kettling can lead to a buildup of steam, which expands dangerously inside the unit with nowhere to escape.