Radiators heat unevenly; some are hot while others remain cold

Safety first: Radiators can be hot; use a cloth or gloves when bleeding.

Steps to check:

• Bleed cold radiators: Focus on radiators that are cold at the top. Bleed until water flows steadily.
• Adjust lockshields: Slightly close the lockshield valves on very hot radiators to encourage flow to cooler ones.
• Check pump speed: Increase pump speed if distant radiators are not receiving enough flow.
• Consider flushing: If some radiators never heat properly, the system may need professional power flushing to remove sludge.

When to call a technician: Persistent imbalance after basic adjustments suggests a need for professional system balancing or cleaning.