Why Is My Radiator Banging?

When radiators in a hot-water system develop banging or hammering noises the problem is most often due to trapped air that cannot get out. Air gets into the system from the fresh water that is periodically added to the system (usually automatically) to replace water that evaporates or leaks out.

How do I stop my radiator from banging?

Use a level, and if you see that the radiator sits level or is tilting away from the valve, intervene. Try slipping a wooden shim or paint stirrer under the legs on the end opposite to the valve. A tilt of only five degrees or so should do the trick.

What causes radiators to make a banging noise?

Air trapped inside the radiator, or the limescale building up on the radiator metal from inside, are the two most common reasons behind this problem. Here is how you can fix a knocking noise coming from radiators. You can let the air out of the radiator by allowing it to bleed.