Impeller for Counter-Current System STP-4000 400VAC - 7017380

Bosta – Impeller for Counter-Current System STP-4000 400VAC (No. 21)

This is the genuine Bosta replacement impeller (part No. 21) designed specifically for the STP-4000-T and STP-4000SS-T counter-current swimming systems operating at 400VAC. The impeller is the core rotating component of the pump, responsible for generating the high-volume water flow that creates the swimming jet. Replacing a worn or damaged impeller restores the system’s full flow performance and protects the motor from overload.

Compatibility

This impeller is engineered exclusively for the Bosta STP-4000-T and STP-4000SS-T counter-current systems (400VAC, three-phase). It is referenced as component No. 21 in the official STP-4000 spare parts diagram. It is not compatible with 230VAC single-phase STP variants or other STP power ratings such as the STP-2200 series. Always verify your system’s model and voltage before ordering.

Why Genuine Matters

Using a genuine Bosta OEM impeller ensures precise hydraulic balance, correct material tolerances, and a perfect fit within the pump housing. Non-genuine alternatives risk vibration, premature wear, and may void any existing system warranty. This part is manufactured to the same specification as the original, guaranteeing reliable, long-term performance in demanding counter-current applications.

Installation

Impeller replacement requires draining and disassembling the pump unit and should be carried out by a qualified pool technician. Refer to the official STP-4000 exploded parts diagram (No. 21) for correct assembly sequence and torque settings. Ensure power is fully isolated before beginning any work on the pump.