How to bleed a radiator

Before you restart your heating, purging of radiators. This simple procedure eliminates the air bubbles trapped in the central-heating system and improves the functioning of it.

Flush the radiator: cut the water supply

Purging is required when the heat radiators gurgle or when little or no at the top. Note that they do not heat the bottom, the problem is different and the purge will rarely effective. Indeed, it is rather a question of balancing and circulator. It is better to speak to the technician responsible for the maintenance of your boiler, remember, is now mandatory once a year.

The most recent installations, the last thirty years, are equipped with a trap, often automatically installed directly on the boiler . Many radiators also have steam traps that do not require intervention. It is not necessary to purge all radiators . The air accumulates in those located in the end network or on the top floor.

See our fact Changing a radiator valve .

How to bleed a radiator

Central heating should be stopped. This means that the pump (pump boiler) should no longer operate. The easiest way is to adjust the boiler to position "was". The ideal is to wait until the radiators are cold . Otherwise, proceed with caution so as not to scald you.

At the top of the radiator is a valve, single or with a thermostatically controlled. The bleed screw is at the other end. According to the model, it is a small brass wheel or some sort of bolt hollow hexagonal shape. To operate the wheel lock pliers enough.For the bolt, it takes a special key butterfly.

Flush the radiator: expel the air

Place a container under the drain plug

Place your pan under the bleed screw. Unlock it a quarter turn, then very slowly until you hear a hissing sound very clearly. After a few moments, the trap also spits water.Leave the drain open again a few seconds and then close it.

Stick to tighten by hand, gently, as you would for a standard faucet. If a small pearl drop after closing, it does not matter.However, if the flow is continuous, so you must force to stop it, it is necessary to replace the drain. Talk to your plumber.

See also our fact sheet: Thermostatic Valve: equip and save .

Bleed radiators: restoring pressure

Partial draining of the central-heating system has broken down the pressure inside the circuit. It is therefore necessary to restore it by adding water. The fill valve is usually below or near the boiler. Open it carefully and watch the gauge on the dashboard of the boiler. Stop filling and close the valve when the needle reaches 1 bar.

NB : If you repeat the operation several times during the same period of heating, suspect the existence of a leak somewhere.

Bleed a radiator: the color of water

Roof drainage

Let the water drain. This water can be gray: that's normal. It contains some of the sludge from the radiator. You've finished serving the radiator when the trickle of water is regular. Indeed as it exits inconsistently, your heater has yet to air.

Bleed radiators: Beware of leaks

Carefully and firmly tighten each screw of each radiator before putting your water supply system started. Check at the screws that water does not ooze. Repeat for all the radiators in your home. Replace faucets at temperatures above normal.