Bleeding out a radiator is an important step to ensure your home is heated all winter long. Bleeding a radiator ensures your most important winter system won’t go out when you need it most. Fortunately, bleeding out a radiator is very simple. The entire process takes about 10 minutes.

Why Bleed A Radiator

Air is prone to getting trapped a radiator, preventing water from heating.

When To Bleed Radiator

You need to bleed out your radiator anytime you have air trapped inside it. You can determine if you have air in your radiator by feeling the top and bottom. If it is warm on the bottom and cool on top, you need to bleed it out. However, if there is a lot of air trapped inside, you will feel that it is cold all over. You need to bleed it out in this case too.

How To Bleed A Radiator

First, you need a radiator key. Most hardware stores will have a key available on the shelves. There are also many radiators that will work with a simple flat-head screwdriver. You should always turn off your central heating system before proceeding with the following steps. Otherwise, more air can get caught inside the radiator. You also want to grab a small bowl that will catch the water as you bleed the radiator. The two valves at the bottom of the unit should be open.

Turn the key counterclockwise on the radiator valve, which is usually located on top. Hold the bowl or a small towel underneath the key to catch any drops. Be careful. This water can be hot and you might hear a hissing sound. Once all the water has dribbled out, turn the key clockwise to close it.

Did You Bleed Radiator Correctly?

Once you have checked each of your radiators, ensure that there are no leaks. Turn the heat on and feel them carefully. If you notice that some of your radiators have more problems than others, it is time to consider that the balance of your radiators might be off. You may need an HVAC pro to fix.


This is a process you should repeat about once a year. It will be one of the easiest home maintenance steps you can take. With just a few minutes of your time, your radiators will be in fine working order