4.9+ Rating 
If your heating system isn’t working as efficiently as it should — for example, your radiators feel cold at the top but warm at the bottom — it’s likely they need bleeding. Trapped air inside the radiator stops hot water from circulating properly, leaving your home feeling chilly and potentially increasing your energy bills.
Luckily, bleeding your radiators is a simple task you can do yourself with minimal tools. Here’s everything you need to know.
Why do radiators need bleeding?
Over time, air can enter your central heating system. This air rises to the top of the radiator and prevents it from heating fully. By releasing (bleeding) this air, you’ll restore proper circulation, improve heating performance, and save energy.
What you’ll need
- A radiator bleed key (you can find high-quality options here)
- A cloth or small container to catch any drips
- A towel to protect your floor
Step-by-step: How to bleed your radiator
1. Turn off your heating
Make sure your heating is turned off and the radiators have cooled completely. This prevents hot water from spraying out and keeps you safe.
2. Locate the bleed valve
Find the bleed valve at the top corner of your radiator. It looks like a small round hole with a square or slotted center.
3. Insert the bleed key
Place your radiator bleed key into the valve. Hold your cloth or container underneath to catch any drips.
4. Turn the key slowly
Gently turn the key anti-clockwise (about a quarter to half turn). You’ll hear a hissing sound — that’s the trapped air escaping.
5. Wait for water to flow
When water starts to trickle out steadily (without sputtering), it means all the air has been released. Quickly turn the key clockwise to close the valve tightly.
6. Check your boiler pressure
After bleeding, check your boiler’s pressure gauge. If the pressure has dropped too low, you may need to top it up according to your boiler manual.
7. Turn your heating back on
Switch your heating back on and check if your radiator is heating evenly. Repeat the process on other radiators if needed.
Helpful tools to make the job easier
At Monsterplumb, we stock everything you need to bleed and maintain your radiators:
- Hinton radiator tools — including radiator bleed keys and other handy accessories.
- SPI radiator draining tools and bungs — perfect if you need to drain your radiator completely for more extensive maintenance or repairs.
When to call a professional
If you’ve bled your radiators and they’re still not heating properly, or you notice leaks or unusual noises, it may be time to contact a qualified heating engineer.
Keep your heating system in top shape
Whether you’re a DIY homeowner or a professional installer, Monsterplumb has a wide range of radiator tools, valves, fittings, and accessories to keep your system running smoothly.
Check out our full range of radiator essentials and get fast delivery across the UK.
Ready to get started? Shop Hinton radiator tools here or SPI draining tools and bungs here and make radiator maintenance simple and stress-free.
