How to bleed a radiator a step by step guide

Bleeding the radiators is a basic element of heating maintenance, making sure that your system works properly and distributes heat evenly. This detail-oriented guide will take you through the simple steps.

 A detailed step-by-step guide poster on how to bleed a radiator. It provides instructions, and essential tips for a proper radiator bleeding process, ensuring efficient heating and a comfortable home environment.

Step-by-Step Guide to Bleeding Radiators:

1. Gather the Necessary Tools:

  • Radiator key or a flat-blade screwdriver.
  • Towels or rags to catch any water drips.
  • A small container to collect excess water.

2. Turn Off the Central Heating:

  • Ensure your central heating system is turned off. This prevents hot water from circulating while you bleed the radiators.

3. Identify Radiators Needing Bleeding:

  • Check each radiator for cold spots or uneven heating. These are indicators of trapped air and suggest that bleeding is required.

4. Locate the Bleed Valve:

  • The bleed valve is typically located at the top of the radiator, either on the side or back. It resembles a square-shaped protrusion.

5. Position the Container:

  • Place the container under the bleed valve to catch any water that may escape during the bleeding process.

6. Open the Bleed Valve:

  • Insert the radiator key or screwdriver into the bleed valve and turn it anticlockwise. You should hear a hissing sound as the trapped air escapes.

7. Wait for Water to Flow:

  • Keep the valve open until water starts flowing consistently without any air bubbles. This ensures that all air is expelled from the radiator.

8. Close the Bleed Valve:

  • Turn the radiator key or screwdriver clockwise to close the bleed valve once water flows steadily. Be ready to catch any last drips with the container.

9. Repeat for Each Radiator:

  • Go through the same process for each radiator in your home, starting from the lowest floor and working your way up.

10. Check the Pressure:

  • After bleeding all radiators, check the boiler pressure and, if necessary, repressurize following the manufacturer's guidelines.


Bleeding radiators is a simple yet essential task to maintain an efficient heating system. By following this step-by-step guide, you can eliminate trapped air, allowing hot water to circulate freely and ensuring each room stays comfortably warm. Regular bleeding contributes to the overall health of your heating system, promoting energy efficiency and even heat distribution.