Key to bleed the heating element
								- key for venting heating elements with container for catching liquid
 - safe and clean ventilation of the heating system
 - for the correct circulation of hot water in the heating system, it is advisable to carry out venting regularly, or at least before the heating season - air in the heating system prevents the circulation of hot water
 -  procedure : 
- put the key on the breather valve - metal part with an inner square
 - turn the hand controller to release the valve
 - after release - due to the pressure in the system, air and liquid will begin to escape
 - as soon as only liquid starts to flow, tighten the valve
 - be extra careful, monitor the amount of liquid in the collection container - if the container is full TIGHTEN THE VALVE and empty the container, if necessary repeat the procedure until it's not just water