Radiators on upper floors stay cold while lower floors heat normally (hydronic IVT furnace/boiler)

Safety: Allow system to cool before bleeding radiators. Protect floors from water spills.

• Check system pressure: Ensure the IVT pressure gauge shows the recommended cold fill pressure. Top up if low.
• Bleed radiators: Starting with upper floors, use a radiator key to open the air vent until water flows steadily, then close.
• Verify pump speed: If the pump has adjustable speeds, set it to a higher setting as per IVT guidelines.
• Recheck pressure: After bleeding, top up the system again to the correct pressure.