During regular use, many users notice that after a radiator has been running for some time, it becomes hot at the top but cool at the bottom, or fails to heat up entirely. Often, this is not due to a fault in the radiator itself, but rather air accumulation within the system, which obstructs the circulation of hot water. Since the heating system operates as a closed loop, air inevitably enters the piping during filling or operation. If not vented promptly, this air collects in the upper part of the radiator, preventing full hot water circulation and reducing heat exchange efficiency. Bleeding the radiator serves to release this trapped air, restoring smooth circulation throughout the heating system. Proper venting not only maximizes the radiator's heat output but also extends the system's lifespan and minimizes heat loss caused by airlocks.
Steel panel radiators are typically designed with an air vent valve at the top, allowing users to periodically release residual air from the system. While the process appears simple, it requires following the correct steps. First, ensure the heating system's inlet valve is closed to prevent a sudden spill of hot water during the venting process. Next, locate the air vent valve at the top of the radiator and gently turn it using a radiator key or a screwdriver. The valve body usually features a slot or groove, with a tiny air outlet hole on the side. As the valve is turned, air escapes through the small hole, accompanied by a faint hissing sound. Once the air has been fully expelled and a steady stream of hot water begins to flow, immediately tighten the valve to reseal the system. After the operation, it is advisable to check the valve connection for cleanliness and any signs of leakage to ensure the system operates safely.
