Experts are warning that hearing a seemingly harmless bubbling sound from your boiler could cost you up to £300 in repairs if ignored, and it’s a tip that could prevent a much larger problem from escalating. According to Gordon Wallis, a sustainable energy expert at Your NRG, homeowners shouldn’t be so quick to dismiss unusual noises coming from their boilers.
He said: “As we move into the warmer months, many households stop thinking about their boilers altogether. But spring is exactly when you should be paying attention to how your heating system sounds – because small issues now can turn into expensive breakdowns by the time autumn rolls around.”
One such noise that should never be ignored is bubbling or popping, often linked to a condition known as kettling.
This happens when limescale accumulates in the heat exchanger, causing water to overheat and produce steam bubbles – and it should be addressed immediately.
“Kettling is more than just a noisy nuisance – it’s a red flag that your system is struggling,” he warned. “Left unchecked, it can seriously damage your boiler, reduce efficiency, and lead to repair costs that easily run into the hundreds.”
For those with oil-fired heating systems, the stakes are even higher. Wallis explains that faulty boilers can waste valuable heating oil – something that’s increasingly costly.
“If your home runs on heating oil, a faulty boiler doesn’t just risk your comfort—it risks wasting a valuable and increasingly costly fuel source,” he said.
“Oil-fired systems are more common in rural areas, where repairs can take longer to arrange. If a problem like kettling causes the boiler to fail, any oil in the system may go to waste.”
Spring is the perfect time to address these issues, not only because it’s easier to book a service but also because service prices tend to be lower.
The expert added: “At this time of year, it’s easier to arrange a service, and prices are often lower. A quick check now could save you not just hundreds in repair bills, but also hundreds in lost oil. That’s money literally going up in smoke.”
In addition to kettling, Wallis pointed out other noises such as hissing or gurgling, which often indicate trapped air, circulation problems, or pressure issues – each of which can reduce the overall efficiency of your heating system.
“If your radiators are hissing or not heating evenly, that’s your system crying out for attention,” Wallis explained.
“These smaller signs can lead to reduced performance and wasted energy if ignored.”
