Overview
- The utility advises using a low-cost bleed key to open the valve and release trapped air so radiators heat to the top.
- Homeowners are told to switch heating off, let radiators cool, and catch escaping water during the five‑minute task.
- British Gas notes pros may charge around £100 for bleeding if people prefer not to do it themselves.
- Cold patches along the bottom indicate likely sludge buildup that restricts flow and requires professional attention.
- If rooms warm unevenly, plumbers recommend balancing radiators using simple tools and step‑by‑step checks, while some experts say to skip foil tricks and focus on maintenance instead.