Bleeding' a radiator is the process of letting any air out of the system to allow water to flow more freely, making your radiators hotter and reducing energy waste. Here, HVAC pros share their top ...

Find the bleed valve, which is usually a small valve on the side of the radiator. Use a radiator key or a flat screwdriver to open it slightly. You'll hear a hissing sound as air escapes; close it ...