ACV A1005253 fan G3G200-gn20-01 CC 340 - 425

ACV A1005253 fan, also listed under catalogue article A1005253, is a combustion air fan of the type used in modulating premix boilers and industrial burners. In room-sealed appliances, this component supplies combustion air and simultaneously drives the flue gases out through the flue system. The fan’s speed is the primary control signal for the firing rate: the burner control varies the fan speed and the gas valve follows proportionally, maintaining the correct air-to-fuel ratio across the modulation range. Selection of such fans is based on required air flow and pressure rise, the direction and orientation of the outlet, impeller diameter, supply voltage, and the control mode (mains on/off, PWM, or 0-10 V analogue). The mounting flange pattern must match the burner or boiler housing. When replacing a fan of this type, check that the communication protocol between the fan’s integral electronics and the boiler control board is compatible; a mismatch can cause speed feedback errors. Typical failure modes include worn bearings (noise or seizure), imbalance from deposits on the impeller blades, a failed run capacitor in the motor, and electronic faults that the boiler reports as airflow or speed sensor errors. Always confirm that the replacement fan is selected for the correct control signal type and output duct orientation.