Radiator Crackling & Other Noises

And we’re back with another talk on radiators – everyone’s favourite topic, it would seem. And you can’t tell me I’m wrong, otherwise, why are you here? Okay, enough with the gentle taunting of my readers – onto business. If your radiator is crackling or making weird noises, it can be downright annoying, if not worrying. Luckily, we’ve got a few tricks up our sleeves to help pinpoint and fix the issue.

A radiator crackling noise is likely caused by built-up air in the pipes. Bleeding your radiator will fix this.

While that’s a nice, short answer for you, we’ve got a few other mystery noises to inspect before we call it a day. Let’s get to it, shall we?

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Radiator Noises & Fixes

First things first, let’s expand on why your radiator is making noise. The most common issues are trapped air, improper tilt, or worst case – pipes warping. Let’s start with the truly easy fixes first, and then we can move onto the more concerning issues.

Radiator Crackling

bleeding radiator

Whether it sounds like someone made a campfire in your radiator, or it’s just an annoying “click” sound, this is generally caused by one thing – trapped air. Luckily, it’s a super easy fix that we’ve talked about several times. Long story very short, you need to bleed your radiators, but we’ll get to that.

Long story slightly longer, let’s talk about why this is happening. Air bubbles are an entirely normal occurrence in your radiator, hence the recommendation that you bleed them annually, generally at the beginning of winter. When your radiator does its thing (you know, radiatin’), it’s moving water through the internal pipes. As the water heats and cools, this can create bubbles of air that get trapped in the radiator.

These bubbles, while normal, can become an issue, so let’s get it sorted:

  1. Crank the heat in your home as high as it goes for ~10 minutes. Now, turn off your radiator and allow it to cool (roughly 1 hour).
  2. Place a towel and bowl or mug below the bleed valve to catch the water that will come out.
  3. Turn your bleed key or screwdriver in the bleed screw until air starts to hiss. Let this continue to happen for ~30 seconds, or until water begins to come out.
  4. Close your bleed screw and turn it all back on. Test, and you should have success!

Read Next: Fix a radiator that won’t turn off.

Banging or Rattling

While this is caused (worst case) by a loose part, another likely solution is that your radiator isn’t tilted properly. Believe it or not, radiators work using gravity! The intake valve uses gravity (thanks to a roughly 5-degree tilt) to get water into the radiator. If it’s either level or tilted the opposite direction, this can’t happen.

Luckily, there’s an easy solution! Tilt your radiator roughly 5-degrees towards your intake valve. This can be done with a piece of scrap wood, a book, sugar packets, whatever – as long as the radiator is tilted, you’re set.

Should this solve the issue, great! If not, you’ll need to call a professional to take a look and ensure nothing else is wrong.

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Squeaking or Hissing

If it sounds like there’s a constant “shush” sound or an annoying squeak you’ve pinpointed to your radiator, there’s a fix. The best part? The fix is cheap.

All you need to do is replace the air vent. This is generally pretty easy to find – just look up schematics of your radiator. They’re generally located in easy-to-reach places because they need to be regularly replaced. If it’s making this noise, it’s likely that you haven’t done that recently, meaning you need to just pop a new one in. They cost next to nothing, and just pop out and back into place – easy!


No, we’re not talking about a nice cup of tea – although the sound is very similar! If your radiator or boiler sounds like a kettle heating up, it’s (unfortunately) a bad sign. It’s likely a sign of limescale or mineral buildup in your radiator, which can block off pipes, causing other issues down the line.

There’s good news and bad – let’s start with the good. The positive side of things is that you’ll only need to clean your radiator! The bad news, however, is that you likely can’t do it. That means calling in a professional and having them likely remove your radiator and clean it. But it’s better than dealing with more serious damage down the line because you couldn’t be bothered to clean it out.

Creaking and Groaning

If there’s a sound you can’t quite place coming from the walls of your home, there’s a potentially very bad cause – pipe warping. You see, radiator pipes contract and expand as they cool and heat (respectively). If they’re built into a wooden frame (like your walls) then it’s possible that the constant change in state is damaging the frame they’re built into.

This is really only an issue if there are wooden joints securing your pipes, and that’s only common in older homes. If, however, you think this is the cause of the sound, don’t hesitate to call a professional. They’ll need to completely replace the bits securing your pipe joints in place with, well, not wood. That’s not something that you want to do. The good news is this is becoming decreasingly common with newer homes, so it’s not the likeliest issue.

Final Thoughts

Radiators make a lot of noise. Some of it is bad, but a good majority of it is totally normal. If you notice one of the above sounds coming from a radiator or the pipes surrounding it, it’s likely time to make a change.

Whether that means bleeding your radiator, slightly tilting it, replacing an air vent, or calling a pro, they’re all necessary actions. Just like everything else in your home, your radiators need constant love and affection. Replace their parts and perform recommended maintenance and you’ll see drastic improvements in both performance and the sounds it makes.