1.a Take down the hose from the float nozzle carefully and remove the whole float from the hanger on the WWTP wall.

1.b If it is a WWTP with the float, placed on an auxiliary board, take out the whole board from the WWTP and remove the float carefully.

2. Take the float into single parts gradually, in order to find out the reason of a damage.

3. The bent or another way damaged spring or the leaky rubber ring on the embedded screw-bolt are the most frequently failure causes. If the failure is revealed, and if it is possible to get rid of this failure, then it is necessary to replace or to repair a fault part.

4. Set the float into the original condition and put it back into the hanger on the WWTP wall. Be mindful of the fact, that the plastic body of the float, which is the water level indicator in the sand filter, has to lead down to the water level. Put back the hose for air supply on the other end of the float, where the air nozzle is situated.