How to Bleed a Radiator and Why You Should Do It Regularly

When your radiators aren’t heating evenly, it’s often a sign that there’s air trapped inside. The good news is that you can fix this quickly and easily by bleeding your radiators. It’s a simple maintenance job that helps your heating system to run more efficiently and helps keeps your home warm and comfortable through the colder months.

What is Radiator Bleeding?
Bleeding a radiator simply means releasing the trapped air inside it. When air gets into the system, it stops hot water from circulating properly, which can leave your radiators only partially warm. In fact, the “air” you’re bleeding is often actually hydrogen gas, caused by internal corrosion within the system. Maintaining the inhibitor levels and minimising the corrosion helps reduce this and it’s something our experts can help you with if you are unsure. By letting the air out, you allow hot water to fill the entire radiator, improving heat distribution and making your heating system more efficient.

What Are the Benefits?
Regularly bleeding your radiators has several benefits. It ensures better heat distribution throughout your home and eliminates cold spots and uneven heating. It can also help reduce energy bills as well-maintained system doesn’t need to work as hard to keep rooms warm. Another bonus is that bleeding your radiators can eliminate the gurgling or knocking noises that often occur when air is trapped in the system. Over time, regular maintenance also reduces wear and tear, helping your boiler and radiators last longer. For most homes, bleeding your radiators once or twice a year is enough.

When to Bleed Your Radiators?
There are a few signs that it’s time to bleed your radiators. If the top of a radiator feels cool while the bottom stays warm or if you hear gurgling or hissing noises when the heating is on, that’s a clear sign of trapped air. You may also notice that your heating takes longer to warm up, or that your system feels less efficient after a long break, such as over the summer months. If any of these sound familiar, it’s worth taking a few minutes to bleed your radiators.

How to Bleed Your Radiators
Before you begin, you’ll need a few simple tools: a radiator key or a flat headed screwdriver, a cloth or towel, and a small bowl or container to catch any water that escapes. To bleed the radiator, start by turning off your heating and waiting until the radiators are completely cool. Find the bleed valve, which is usually located at the top corner of the radiator and place your bowl and towel underneath it. Insert the radiator key into the valve and slowly turn it anti-clockwise. You’ll hear a hissing sound as the trapped air escapes. Once water begins to trickle out steadily, close the valve by turning it clockwise without overtightening.

Finally, turn the heating back on and make sure the radiator heats evenly from top to bottom. If it’s still not warming properly, repeat the process or move on to the next radiator, starting with the one furthest from your boiler.

Try to bleed your radiators once a year, ideally in autumn before the cold weather arrives. Always start with the radiator furthest from the boiler and keep an eye on the boiler pressure after bleeding. If the same radiator continues to give trouble, or you still notice cold spots or noises, there may be another issue within the system that needs professional attention.

Bleeding your radiators is one of those small maintenance jobs that makes a big difference. It improves comfort, efficiency and can even help reduce your energy bills. If you’re not confident doing it yourself or if your heating system still isn’t performing as it should, our HandyExperts are here to help. We can check your central heating system and make sure everything’s running safely and efficiently so you can relax and enjoy a warm, cosy home.