De Dietrich S100886 RG118 - R14,2x1 fan

This fan is a combustion air and flue gas exhauster for room-sealed boilers and burners. In a modulating premix burner, the fan speed determines the firing rate; the burner control varies the speed and the gas valve follows accordingly. Parts of this type are selected by required air flow and pressure, outlet orientation, impeller diameter, voltage, and control mode—mains frequency or modulated signals such as PWM or 0-10 V. The flange pattern must match the burner or boiler mounting. Typical failure modes include worn bearings, impeller imbalance from deposit buildup, a failed run capacitor, or speed feedback errors that the burner control registers as an airflow fault. When replacing such a fan, confirm that the new unit has the same outlet direction and electrical connections as the original. Check the control signal type: some boilers use a simple mains supply, while others require a separate speed-control signal. Also verify the pressure output, as incorrect pressure can cause poor combustion or safety lockouts. No compatibility with specific boiler models or performance ratings are stated for this article. The manufacturer code S100886 and catalogue reference 375.145.059 identify the part; ensure these match the original before ordering.