How to Bleed a Central Heating System

What You'll Need
What You'll Need

Bleeding a central heating system may sound difficult for someone who has to fix the entire system, but it is a simple and safe procedure. Bleeding a central heating system implies that there is air trapped in the heating system and it is hampering the process of heating due to its presence. Sometimes air is trapped in the upper portion of the heater and may cause difficulty for the system to produce heat as output. In such cases, ‘bleeding’ is required for the heating system as it helps to release the air present within the mechanical body. Here are several guidelines to help you with your problem.

Step 1 – Open the Valve of the Heating System

Every heating system or radiator comes with a special tool called a ‘bleed key.’ Along with the bleed key there is a ‘bleed valve’ that is a particular protrusion at the top of the heating system. You must open the valve several inches to allow the unnecessary air to escape from the heating system. Be careful not to let the water escape the heating system.

Step 2 – Reduce Overall Pressure

In a sealed heating system, you will have to reduce the overall pressure of the radiator in order to keep the volume of the water and the presence of air at stable levels. It is always wise to consult the manual provided with your heating system.

Step 3 – Turn the Valve

Be very careful while turning the valve. Keep a small piece of cloth along with you so that you may clean up any water drops that may escape from the heating system and drip on the floor. Also, make sure to keep your hands are at a safe distance so that no injury is received during the procedure

Step 4 – Bleed the Unit

Turn off the central heating system so that you may import air into the system. Then fit the bleed key into the bleed valve and carefully turn it counterclockwise but only a few centimeters. You will hear the air escaping the heating system with a hissing sound. As soon as the water dribbles out, the air will begin escaping the system. Gently turn the bleed key back to its previous position. Make sure you have tightened it carefully.

Step 5 – Cleaning Up

You will now have to clean the water that has managed to escape from the central heating system. You can use a cloth rag, tissue or a wiper to keep the floor clean. Make sure to have tightened the valve shut so that no more water is lost. Air will have left the body of the machine by now.

After you are done with bleeding the central heating system, the heating done by the mechanical body will be much more efficient and secure. If the problem still persists, consult a trustworthy HVAC professional.