Which submersible pump do I need? Complete buying guide

Quick selection per situation

Question 1: What kind of water are you pumping?

Clean water (rainwater, leakage water, groundwater without sand) can be handled by any submersible pump. For lightly polluted water with some sand or small particles, choose a drainage pump. Dirty water with leaves, sludge, fibers, or wipes requires a dirty water pump with a vortex impeller and large free passage. If there's sand or concrete in it, like on a construction site, you'll need a wear-resistant pump. More explanation: which impeller suits which water.

Question 2: How big are the solid particles?

Look at the free passage: the largest particle that can pass through the pump unimpeded. A flat suction pump for clean water allows only 1 to 3 mm, a drainage pump about 10 mm, and a dirty water pump 28 to 50 mm. If the passage is too small, the pump will clog. Read how large the passage should be.

Question 3: Does the pump need to operate automatically?

If the pump is permanently installed in a pit, basement, or crawl space, you'll want a float switch or sensor that automatically turns it on and off. If you use the pump occasionally and stay with it, a pump without a float switch will suffice. In narrow pits, a regular float switch often doesn't fit; in that case, choose a pump with an integrated float switch or an electronic sensor. More: with or without float switch.

Question 4: How dry does it need to get?

A regular submersible pump leaves a few centimeters of water, as the inlet is higher than the bottom. If you want the floor to be (almost) dry, for example in a basement, on a flat roof, or in a crawl space, choose a flat suction submersible pump that pumps down to approximately 2 mm.

Question 5: How much water and how high?

This determines the capacity. Calculate how many liters need to be removed and how quickly, and add up the head: the height difference plus approximately 1 meter per 10 meters of hose. Compare this with the pump curve: the flow rate on the box applies at 0 meters of head and decreases as the water needs to be pumped higher. Step-by-step: calculating head and flow rate.

Also pay attention to the voltage: for home use, 230V with a plug is convenient. Heavy-duty construction and dirty water pumps are often (also) available in 400V.

Recommended pumps

BASEMENT AND SUMP

HOMA Bully C 140 WA

All-round basement pump with float switch and cooling jacket, for clean and lightly polluted water.

€366.95

View pump

FLOOR DRY – AUTOMATIC

Simer 6 + CRAB float switch

Flat suction pump down to 2 mm with CRAB sensor, switches on and off automatically.

€339.80

View pump set

DIRTY WATER

HOMA TP28 dirty water pump

Cast iron dirty water pump with 28 mm free passage, with or without float switch.

from €1,274.95

View pump

Specific situation? Read basement flooded, crawl space full of water, or keeping a construction pit dry.

Frequently Asked Questions

Which submersible pump is best for a basement?

For clean to lightly polluted water, a drainage pump with a float switch, such as the HOMA Bully C 140 WA. If you want the floor almost dry, choose a flat suction pump with a sensor.

What is the difference between a clean water and a dirty water pump?

The free passage: a clean water pump allows a few millimeters, a dirty water pump 28 to 50 mm. Using dirty water in a clean water pump will quickly clog it.

How many liters per hour do I need?

Divide the volume by the desired pumping time and check the pump curve to see if the pump achieves that flow rate at your head. For a basement, 4,000 to 8,000 liters per hour is common.

Do I need a submersible pump with a float switch?

Yes, if the pump is fixed and needs to operate independently. For temporary use where you stay with it, a pump without a float switch is sufficient.