Radiators on upper floors are cold while lower ones heat normally when the Viadrus furnace is running.

Safety: Allow system to cool before bleeding radiators.

• Bleed upper radiators: Starting from the top floor, bleed each radiator until water flows without air. Monitor and maintain system pressure.
• Increase pump speed: Set the circulation pump to a higher speed to improve flow to upper levels.
• Check balancing valves: Ensure that any balancing valves on lower circuits are not overly throttled, which can starve upper circuits.
• Automatic air vents: Verify that automatic air vents at high points are open and functioning.