When there is a lot of counter-pressure in the smoke exhaust due to wind. The Condensagaz and Optimagaz pressostat might block the start of the boiler as the ventilator has trouble starting.

To prevent the wind to push the air in the wrong direction through the boiler's heat exchanger a one-directional ball bearing is installed. When executing this procedure it is advisable to replace the start capacitor of the ventilator motor. Because the counter-pressure of the wind will have increased the starting currents through this capacitor.