How to Bleed a Hot Water Boiler
A hot water boiler system includes a boiler furnace, carrier pipes and radiators. Occasionally, air pockets develop. Since hot air rises, they rise and settle inside the radiators and block the flow of heat. To alleviate pressure, the radiators, rather than the boiler, needs to be bled. Bleeding is accomplished by twisting a small valve on the side of the radiator. To economize time, enlist a helper to complete the task. One individual can attend to the radiator while the other calls out changes in the gauge reading. Does this Spark an idea?
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Things You'll Need
- Safety glasses
- Towel
- Plastic container or cup
- Radiator key
- Screwdriver
- Pliers
Instructions
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Check the radiator for heat conduction. If the radiator is running and one or more chambers are cold, there is air in the line. It is not uncommon for one chamber, commonly called fins, to be cold to the touch while the others are hot.
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Read the gauge located on the boiler. A gauge check is the second method to determine that the line requires bleeding. A needle points to the approximate amount of pressure expressed in pounds. For every two feet the heat must travel upwards, one pound of water pressure is required. In of a two story home, 12 to 15 pounds of pressure is acceptable, as the heat rises 25 to 30 feet.
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Place a towel on the floor at the side of the radiator or hold a plastic cup underneath the valve to protect the floor or carpet. Don safety glasses to shield eyes from hot water or steam.
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Locate the valve key. If there is none, purchase a substitute key at the hardware store. For a makeshift key, retrieve pliers and a flat head screwdriver from the toolbox. Place the screw driver in the valve socket and clamp the pliers onto the screw driver handle. The pliers will create a handle for leverage. Turn the key slowly. Only a small increment is necessary. The valve hisses when pressure is relieved. When a small amount of water dribbles out, the valve is sufficiently open.
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Read the information on the boiler gauge. Return to the basement or have a helper shout out the results. Open, then close, the boiler valve. It is located on the pipe just above the boiler furnace. This releases water into the system. The gauge will indicate the pressure has returned to acceptable levels, or the pressure may be slightly low. To increase pressure, add water to the radiator.
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Tips & Warnings
A third tool option for a makeshift radiator key is a half-inch 12-point socket wrench.
References
- Photo Credit Jupiterimages/liquidlibrary/Getty Images
