Practical guide on how to vent your radiator and why it is so useful.

Do the radiators in the home not have a homogeneous temperature over the entire surface, or are the pipes cold at the top and you often hear noise when they are on?

SeIf the answer is yes to one or all three cases reported, then surely inside the radiators there is an accumulation of air that, like a bubble, prevents the hot water from circulating properly causing the lowering of the operating pressure of the hydraulic system and sometimes the blockage of the boiler itself, all this going to reduce the heat output of the heating body.  .  

To eliminate this air bubble, the radiators must be vented.

The operation is very simple and fast to perform, just follow step by step some suggestions. Here are which ones:

The first thing to do to vent the radiators, if the heating is autonomous, is to turn off the boiler or the circulation pump..

Then slowly open the vent valve by simply turning it counterclockwise to the end of its travel.

The vent valve is located in the upper part of the radiator, generally on the opposite side of the thermostatic valve, at the pipe that comes out of the wall and brings water to the radiator. It is important to remember to place a container under the valve that can collect the water jet that will come out once the air is exhausted.

To open the valve you can use the appropriate key or a simple screwdriver.

Let all the air out of the radiators until the air starts coming out of a water jet constant. Then you have to close the valve again.

If the pressure should be lower, it is necessary to restore the correct operating pressure by turning the appropriate knob in the boiler itself.
After having vented the radiators, it is necessary to check the water pressure of the radiators through the pressure gauge of the boiler whose dart must be positioned between the value 1 and the value 2.

At this point, simply restart the system by turning the boiler or circulation pump back on and check that the radiators heat evenly.

 If not, it means that there is still too much air inside and it will be necessary to repeat the operation.


Irsap for the environment

Photovoltaic production
Actual Power
0,00 kW
Produced power
8.599.128,26 kWh
CO2 emission
3.491,25 t