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AnswerHow do you bleed a radiator?
Turn off the heating, hold a cloth under the bleed valve at the top of the radiator, and turn the bleed key anticlockwise until trapped air hisses out and water appears — then close it.
In more detail
Bleed radiators when the top is cold but the bottom is warm. Re-check your boiler pressure afterwards and top up if needed.
2026 figures · BTU uses standard UK heat-loss methodology; running costs use the Ofgem price cap · always confirm with a professional.