Air out, heat in: vent gurgling, lukewarm radiators

Do you still remember last winter: Did the water in the heater chuckle or did it only partially warm up? Then now is the time to vent.

The radiators do not always have to be vented at the start of the heating season – you can hear and feel it when it becomes necessary.

How do I know when the radiator should be vented?

The DIY Academy explains if the radiator does not get really warm, especially in the upper area, despite the thermostat valve being fully opened, or if the water in it makes gurgling noises. Then there is air in the pipes that you have to let out.

How do I bleed?

Use a square wrench to open the valve on the side of the radiator and leave it open until there is only water left. But do not turn the valve all the way out.

You catch the water with a bowl. If a lot of it comes out before you can quickly close the valve again, you have to refill the heating water. A pressure drop can be seen on the manometer on the system in the basement.

The DIY Academy even recommends checking the water pressure on the heating system beforehand and, if necessary, refilling it with water. In addition, you should, if possible, switch off the heating circulation pump before venting.

How do I top up with water?

This can be done directly on the system – and preferably in such a way that new air bubbles are not trapped again. The DIY Academy therefore advises first filling the hose for the inlet valve of the heating system with water. Just turn on the tap for a moment. Only then does the hose come to the valve. Now the tap and the valve on the device are opened one after the other.

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How much water has to be topped up and how high the water pressure should be depends not only on the heating system in question, but also on its location in the building and its height. Either the pressure gauge shows the optimal water pressure with a green marked area or you can find the bar information in the operating instructions, according to the DIY Academy.

The experts point out that this is the procedure for older systems in existence. It can look different with modern systems – for example, you may have to use special heating water instead of tap water. If there is nothing about this in the operating instructions, you should ask your heating installer for instructions specifically for this.