Why is my radiator making a noise?

Noisy radiators are a lot like noisy neighbours; nobody wants them!

Whilst certain sounds can be pretty normal, indicating little more than water flowing through the radiator pipes in your home, other noises can signify more serious issues.

If this happens to be the case, identifying the issue and getting it fixed promptly is crucial. Radiators are a vital feature of our heating systems here in the UK, so finding that they're not working correctly can be a huge headache.

Knowing how to repair your radiators starts with knowing what's causing them to make a noise in the first place. To help make this process easier, our central heating experts have compiled a list of the most common reasons why your radiators might be making noise, what these noises sound like and the steps you'll need to take to address them safely.

In this guide, we'll cover:

• Clicking noises
• Gurgling noises
• Banging noises
• The sound of water running
• Whistling and hissing noises

Why are my radiators and or pipework making a creaking or clicking sound?

Creaking or clicking sounds can normally be caused by the pipework or the radiators themselves expanding and contracting as the heat in the system affects their structure. This noise can be caused by numerous issues.

1. Radiator brackets may have been fitted too tight which can produce noise as the radiator expands against them.
2. Pipework that is supported incorrectly and has too much movement in it as the pipes expand.
3. Pipework that is fitted too near a joist notch or other surfaces, such as a floorboard, again causing noise as the pipework expands and rubs against it.  
4. Clicking could be caused by solid debris within the system being pushed round the system and hitting the wall of pipework or radiator.

Why is my radiator gurgling?

If your radiator is making a gurgling sound it usually indicates there is trapped air within the system or the velocity of the water in the system being too great.  Below are some causes of these issues.

1. Water velocity

If the water is flowing too quickly it can create turbulence and unsettle your radiator, causing gurgling or whooshing sounds as it passes through radiators and pipework. This can be caused by how the system has been piped up. On older appliances or systems with fixed speed pumps, the gurgling may be caused by the pump moving too much water for the size of the system it is connected to. 

2. System pipework configuration

If you have an open vented system, there could also be issues with how it is piped up. If the pipework is not configured correctly, it will cause air to be drawn into the system which then can end up causing noise within the system and radiators when it gets trapped. The only way to rectify this is to get a professional to re-pipe the system to prevent this happening again.

3. Corrosion within the system

If your system has corrosion within it due to the reaction between dissimilar metals and water, this process can produce gas which, just like air,  can cause noise and other system issues. This can be resolved by having the system flushed and treated with chemicals to prevent this happening again.

4.  Low system water pressure

Low water pressure within your sealed central heating system could also cause air and noise within the system. Check for leaks and repressurise your system.  If the issue persists you would need to contact a professional heating engineer.  

Why is my radiator banging?

A banging radiator can be caused by a number of factors, including:

1. Loose or faulty components

Loose pipes, fittings, or radiator brackets can cause the radiator to vibrate or move when the heating system is in operation.

2. Water flow issues

Problems with water flow, such as a blockage or restricted flow due to sediment buildup or  more commonly a faulty pump, can lead to banging noises as the water struggles to circulate properly, which causes the water within the boilers heat exchanger to overheat and start to boil.

3. Air in the system

Air trapped in the heating system can create an air lock which can potentially stop the water flowing and lead to banging noises. To fix this issue, try bleeding the radiator that's making noises using your radiator key.

Why is my radiator hissing?

This could be caused by an open bleed valve allowing air to be released from the radiator. To stop this, simply close the valve. If this does not stop the noise contact a professional Gas Safe registered engineer to replace the bleed valve. 

DIY fixes for common radiator noises

If your radiator is making a noise, a simple DIY fix could get everything working properly again. If you don’t feel comfortable carrying out any of these yourself, always seek professional help to avoid making any issues with your radiators worse.

1. Bleed your radiators

Bleeding your radiators will get rid of air pockets and enable hot water to circulate around your central heating system more efficiently.

To bleed your radiators, you’ll need a radiator bleed key and an old jug to catch any water that escapes.

Before you start bleeding your radiators, make sure your central heating is turned off, and the radiators are cool. Then, put the radiator bleed key into the bleed valve, placing the jug underneath to collect any water.

You should twist the key anti-clockwise until you hear a hissing sound (this is the air escaping), and tighten up the valve once the water starts to leak out. You’ll have to repeat this on each radiator that you think needs bleeding.  If you have multiple radiators to bleed, start with the one furthest away from your boiler.

2. Tightening loose fittings

If you think loose fittings could be the cause of any clunking or banging noises, the first thing you need to do is carefully inspect the pipes, brackets, and fittings connected to the noisy radiator. If anything is moving in ways it shouldn’t, tighten them using a wrench or spanner.

Just make sure your heating is switched off before starting to avoid burning yourself.

3. Check your water pressure

If your boiler’s water pressure is low, it can lead to air becoming trapped in your heating system.

Typically, boiler pressure should be between 1-2 bars, with the optimal range being highlighted green on the pressure dial and red indicating high and low pressure.

Read our full guide on boiler pressure for more information.

4. Check for leaks

As well as causing leaks, cracks in pipework can introduce air into your heating system. If you suspect a leak or notice any water dripping, you must act quickly to avoid damages getting worse.

DIY and hardware shops will sell pipe repair kits that you can use to fix cracks or leaks without replacing pipes; however, if the problem persists, you must call in a Gas Safe registered engineer to assess and remedy the affected area. 

5. Replace your radiators

Sometimes, no amount of fixes will stop a noisy radiator from making a racket. Older central heating systems and radiators are especially prone to making whistling, clicking, gurgling or banging noises, and in these situations, the only real solution is to replace your radiators with newer models.