A circulation pump circulates coolant through the fluid circuit, i.e. and the heater itself. The circulation pump is activated by the control unit and operates for the entire duration of the heater operation. (including during the adjustment pause)
A decrease in the performance of the circulating pump can occur due to contamination of the gap between the impeller magnet and the hermetic bulkhead. Termination of circulation is possible due to: severe contamination of the gap between the impeller magnet and hermetic bulkhead, damage to the impeller or breakdown of the pump. To remove dirt, remove the pump, remove the impeller from it, and blow it with compressed air. When reducing the performance of the pump should also check: Number of antifreeze in the circuit, the state of the liquid hose (for wrinkles), the state of valves in the heater circuit, the quality of antifreeze used (for fluidity at low temperatures).
1. Remove the heater.
2. Disconnect the electrical connectors.
3. Remove the screws.
4. Remove the mounting clamp and the circulation pump.
5. To carry out work on the repaired units.
Note: In fig. provided heater T90 ST. With the T90 S heater, the control unit can also be located on the blower cover, which does not affect the replacement of the circulation pump.
1. Lubricate the sealing ring (with technical petroleum jelly).
2. Install the circulating pump, fasten with the mounting clip and screws.
3. Torque for screws 3 Nm ± 10%
4. Connect the electrical connectors.
5. Install the heater.