If your radiator has started making strange noises — whether gurgling, banging, or hissing — it’s your heating system’s way of telling you something’s not quite right. While some noises are harmless and easily fixed, others can signal deeper issues that require a professional touch.
As a heating installer, I often meet homeowners who’ve tried bleeding their radiators or adjusting valves, only to find the noise returns. Knowing when to call in an engineer can save you from costly repairs and improve your heating system’s efficiency.
When It’s Just a Minor Issue
Before you panic, a few common radiator noises have simple explanations.
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Gurgling – Usually caused by trapped air in the system. Bleeding your radiators with a radiator key often solves this.
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Hissing or Whistling – Often linked to partially closed or faulty radiator valves. Make sure they’re fully open and in good condition.
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Light Tapping – This can occur when pipes expand slightly as they heat up. It’s usually harmless unless the noise becomes frequent or loud.
If these sounds are occasional and your radiators are still heating evenly, you’re likely dealing with a minor issue.
When to Call a Professional
Persistent or loud radiator noises can be signs of underlying system problems that need expert attention. You should contact a heating engineer if:
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The noise returns after bleeding the radiators — this can mean there’s a circulation issue or sludge buildup in the system.
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You hear loud bangs or knocking — possibly caused by blockages, trapped debris, or water hammer.
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There are cold spots on your radiators — indicating poor water flow, often due to sludge or rust inside the system.
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Your boiler pressure keeps dropping or rising — noisy radiators can be a symptom of incorrect system pressure.
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You’re hearing whistling from multiple radiators — suggesting a system imbalance or pump fault.
A professional can carry out diagnostics, check your pump and valves, and ensure the system is balanced for even heat distribution.
What a Heating Engineer Can Do
When we’re called out to inspect noisy radiators, we typically:
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Flush the system to remove sludge and debris.
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Check the circulation pump for faults or blockages.
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Inspect radiator valves and thermostatic controls.
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Ensure your system pressure is correctly set and stable.
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Balance the system so all radiators heat up evenly and quietly.
This not only quietens the system but also improves energy efficiency, helping your boiler run more smoothly and last longer.
Could the Noise Be Coming from the Boiler Itself?
Sometimes the radiator isn’t the real culprit — it’s the boiler.
Older boilers can become less efficient over time, causing fluctuating water pressure, uneven heating, and loud operation. If your system is over 10–15 years old and you’re dealing with repeated noise issues, it might be time to consider a modern boiler upgrade.
Today’s boilers are quieter, more efficient, and designed for long-term reliability. An upgrade can often solve ongoing radiator noise problems while lowering your heating bills.
Keep Your Heating System Quiet and Efficient
If your radiators are noisy, don’t ignore it — it’s usually an early warning sign.
Addressing the problem promptly can:
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Prevent costly boiler damage.
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Improve heating performance.
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Reduce your energy bills.
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Extend the life of your system.
At A N Heating Ltd, our experienced engineers can quickly identify the source of radiator noise and recommend the right fix — from a simple system flush to a new high-efficiency boiler installation.
Get Professional Help Today
If your radiator noise keeps coming back or you’re unsure what’s causing it, it’s time to speak to a professional.
Call 01225 708 562 or contact us online to book a heating service. We’ll get your system running quietly and efficiently again — so you can enjoy a warm, peaceful home.