Bleeding a radiator is a simple way to get rid of trapped air so your heating works properly. Here’s a clear step-by-step you can follow:
🧰 What you’ll need
- Radiator key (or a flathead screwdriver for some models)
- Cloth or towel
- Small container or bowl
🔧 Step-by-step guide
1. Turn the heating off
- Let the system cool completely.
- This prevents hot water from spraying out.
2. Locate the bleed valve
- It’s a small square or slotted screw at the top corner of the radiator.
3. Prepare for water
- Hold your cloth and container under the valve to catch drips.
4. Open the valve slowly
- Turn the key anti-clockwise (left) about a quarter turn.
- You should hear a hissing sound—that’s trapped air escaping.
5. Wait for water
- Once the hissing stops and a steady stream of water comes out, the air is gone.
6. Close the valve
- Turn it clockwise (right) until snug (don’t overtighten).
7. Check boiler pressure
- Bleeding can reduce pressure.
- If needed, top it back up to around 1.0–1.5 bar.
8. Turn heating back on
- Check if the radiator heats evenly (top and bottom).
💡 Signs your radiator needs bleeding
- Cold at the top, warm at the bottom
- Gurgling or bubbling noises
- Takes a long time to heat up
⚠️ Tips
- Start with radiators downstairs, then move upstairs.
- If multiple radiators need bleeding, check pressure at the end.
- If a radiator stays cold after bleeding, there may be a different issue (like sludge or a valve problem).