Bleeding underfloor heating

Bleeding the underfloor heating is very important for the proper functioning of the system, in this way air bubbles are removed from the system. The air bubbles have a negative effect on the functioning of the underfloor heating system because it makes the heat circulation more difficult. You can easily bleed underfloor heating yourself, provided you follow the right steps and have the right tools.

 

There are signs that indicate when it is time to bleed your underfloor heating. These signs are explained below:

• Cold spots on the floor
  If you notice that there are cold spots in certain parts of the floor, it is time to bleed the underfloor heating system.

• Bubbling sounds
  If you hear bubbling sounds, you know that the system needs to be bled.

• Increased energy consumption
  Increased energy consumption is also an important signal, because if the underfloor heating is inefficient, more energy has to be used to achieve the same temperature.

• Irregular operation of the thermostat
  Erratic thermostat operation is also an important factor to keep an eye on.

 

Bleeding the underfloor heating is necessary for both district heating and your own central heating system. The bleeding process does not differ much between the two systems. With district heating, you must take into account a higher system pressure that can sometimes be present. With your own central heating system, you can monitor the pressure of the system yourself and top it up if necessary.​

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Materials Needed​​

For bleeding underfloor heating it is important that you use the right materials. You may need these materials: bleeding key, bleeding stopper and bleeding plugs.

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​​​​Step-by-step plan for bleeding water-based underfloor heating 

​Water-based underfloor heating systems, for example from the Magnum brand, contain an automatic air vent. If there is a risk that the space in which the underfloor heating is installed can cool down to freezing point, the system must be pressurised with air. In that case, the following steps are important:

Step 1: Turn off the water

• For open manifolds: close the ball valves.

• For manifolds with pump: close the thermostatic valve in the supply and the ball valve in the return of the manifold.

Step 2: Opening flow meters

Open all flow meters and shut-off caps or thermostatic group valves.

Step 3: Using the compressor
Connect a compressor to the filling nipple and open it using the recess in the closing cap.

Step 4: Testing

Then test the system for air tightness with the connected compressor (maximum 4 bar).

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​Frequency of underfloor heating maintenance

It is recommended to bleed underfloor heating at least once a year. It is important to respond to signals of possible air bubbles in the system. The clearest signal is cold spots or that certain parts of the floor do not get warm. In addition, hearing bubbling sounds is a second signal that there are air bubbles in the heating system. Also keep an eye on the energy consumption. The air bubbles prevent the efficiency of the heat circulation, which means that more heating is required. In addition, irregular functioning of the thermostat is also an important indicator of air in the heating system.

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