Closeup of someone bleeding a white radiator with a green cloth

Plumbing, heating and gas advice from Plumbing on Demand

How Do I Bleed a Radiator?

If your radiator feels hot at the bottom but cold at the top, it’s likely that air has become trapped inside the system. This trapped air stops hot water from circulating properly, reducing the radiator’s efficiency.

Bleeding a radiator releases this trapped air and allows the heating system to work as it should. This simple maintenance task can improve heating performance and even help reduce energy costs. 

Closeup of someone bleeding a white radiator with a green cloth

Signs Your Radiator Needs Bleeding

  • The top of the radiator feels cold
  • The radiator makes gurgling noises
  • Your home takes longer to heat up

 

Step-by-Step Guide

  1. Turn off the heating system and allow the radiator to cool.
  2. Place a cloth or towel beneath the bleed valve.
  3. Insert a radiator bleed key into the screw valve.
  4. Turn the key slowly anti-clockwise.
  5. You will hear a hissing sound as trapped air escapes.
  6. Once water starts to drip out, close the screw valve again.

 

Once finished, check your boiler pressure and top it up if necessary.

Need Help with Heating Issues?

If bleeding the radiator does not fix the problem, there may be a deeper issue such as sludge build-up or circulation problems.

The team at Plumbing on Demand can diagnose heating faults quickly and ensure your radiators work efficiently throughout the colder months.

Frequently Asked Questions (FAQs)

To fix a cold radiator, start by bleeding it to remove trapped air, which is the most likely cause. Common fixes involve turning the heating off, using a radiator key and checking boiler pressure. But if you are not confident doing this, call us at Plumbing on Demand for step-by-step advice or further assistance.

Adam Goldman of Plumbing on Demand is highly recommended by his clients. He specialises in all kinds of plumbing, heating and gas issues.

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