Parts of a Pool Pump – Strainer Pot, Impeller, Seal, Motor

All 14 parts on the diagram

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Start here: 5 main parts 5

Strainer pot The chamber at the front of the pump that holds the basket.
Strainer cover (lid) The lid on the pot; it comes off to reach the basket.
Motor The electric motor that spins the impeller.
Strainer basket A basket in the pot that catches leaves, hair and lint.
Impeller The spinning wheel with vanes that moves the water.

The pump from the side 3

Suction port The opening where water from the pool enters the pump.
Discharge port The opening where water leaves the pump for the filter.
Drain plug A plug at the bottom; removing it empties the pump.

The pump cut through 6

Cover O-ring A ring that seals the cover to the pot.
Volute (pump housing) The casing round the impeller that leads water to the outlet.
Diffuser A fixed shroud round the impeller that guides the water.
Seal plate The plate that closes the pump's back and holds the seal.
Shaft seal A seal round the shaft that keeps water out of the motor.
Motor shaft The shaft that carries the motor's turning to the impeller.

How this list was compiled: Read 2026-09-30, for names only; a name is kept only where two unrelated sources use it. Makers are not named on the page. (1) A pool pump maker's installation and operating instructions, https://archive.org/details/manuallib-id-2704091 : strainer housing, strainer cover, strainer basket, diffuser, impeller, seal plate, shaft seals, motor shaft, motor, drain plug(s), suction and discharge pipes. (2) A second maker's user's guide, https://archive.org/details/manualsbase-id-653348 , and the manual of a brand in the same group, https://archive.org/details/manuallib-id-2704739 , counted as one: strainer pot (the unit in front of the volute, with the basket inside), lid and cover O-ring, volute, diffuser, impeller, seal plate, shaft seal, motor shaft, drain plug, suction port, discharge port. (3) A third maker's manual, https://archive.org/details/manualzilla-id-7259683 : strainer cover, strainer body, basket, O-ring on the cover, shaft seal, drain plug, pump inlet, pump discharge. (4) A fourth maker's manual, https://archive.org/details/manualzilla-id-7388362 : hair and lint strainer pot and its lid, basket, suction port, shaft seal, volute, diffuser, impeller. (5) A fifth maker's guide, https://archive.org/details/manualsonline-id-2a058739-5441-41d0-a623-5fcdf50073b8 : strainer basket, O-ring, diffuser, seal plate, impeller, motor shaft, drain plugs. (6) Wikipedia, Centrifugal pump (fluid enters the impeller near its axis and is flung outward into a diffuser or volute chamber, the casing, from which it exits; the turning comes from an electric motor) and Swimming pool sanitation (a small filter basket in the pump keeps leaves and hair from the impeller). Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry; nothing traced. Licence: own work

How it works

A pool pump has a wet end and a motor. The first view names what you can see from outside; the second cuts the pump open along its shaft.

Read the full guide

From the side

Water enters at the suction port, in the side of the strainer pot. The strainer cover on top comes off to reach inside. Water leaves at the discharge port. The motor sits behind the pump, and drain plugs underneath let the water out.

Cut through

The strainer basket in the pot catches leaves and hair, and an O-ring seals the cover. In the volute, the impeller spins inside the diffuser and flings water out toward the discharge. The seal plate closes the back of the volute; the motor shaft passes through it, and the shaft seal keeps water out of the motor.

Some makers call the strainer pot a strainer housing, a trap or a hair and lint pot.

Questions and answers

What are the parts of a pool pump called?

At the front: the strainer pot, its cover and O-ring, and the strainer basket. In the middle: the volute, diffuser, impeller, seal plate and shaft seal. At the back: the motor and its shaft. Water enters at the suction port and leaves at the discharge.

What does the impeller do in a pool pump?

It is the wheel with vanes on the end of the motor shaft. Water enters at its center, and as it spins it flings the water outward into the volute, which leads it to the discharge port.

What is the basket in a pool pump for?

The strainer basket sits in the strainer pot, ahead of the impeller. It catches leaves, hair and lint so they do not reach the impeller.

What is the seal plate on a pool pump?

The plate between the pump and the motor. It closes the back of the volute and holds the shaft seal, which keeps water from following the motor shaft into the motor.