Some radiators or baseboards are hot at the top but cold at the bottom, or vice versa

Safety first: Use caution when bleeding radiators; water may be hot. Protect floors from drips.

• Bleed radiators: Starting with the highest radiators, use a radiator key or screwdriver to open the bleed valve until air stops and water flows steadily, then close.
• Check system pressure: After bleeding, verify pressure is still adequate (around 12–20 psi). Add water if needed.
• Clean or flush emitters: If a radiator remains cold, it may be clogged with sludge. A professional can flush or power-clean the system.
• Adjust balancing valves: Throttle hotter zones slightly to encourage flow to cooler areas.