Centrifugal pump for a water butt

Updated: 22 October 2026

You have roof water in a butt and you want a hose.

You have roof water in a butt and you want a hose. A centrifugal pump for water butt work belongs beside that tank, primed, inside its suction figure, on clean enough water, and off the drinking-water main unless a proper arrangement is in place. Sizing stays on the centrifugal pump buying guide. The fill steps are on how to prime a centrifugal pump. Who each listing fits is on the best centrifugal pump page. The seven ASINs sit on the centrifugal pump comparison. Peter F., editor for DIY & tools, updated this on 22 October 2026. We did not install these pumps. A qualifying purchase can earn a commission at no extra cost to you.

Our top picks

Badge	Product	Stated suction	Self-priming	Clean water	Note	Price	Offer
Best overall	KATSU Tools KATSU 151116	8 m	No	Yes	8.8	about £69.99	View offer
Best value	KATSU Tools KATSU 151112	8 m	No	Yes	8.0	about £49.99	View offer
Alternative	Clarke Clarke ECP15A1	n/a	n/a	n/a	7.0	about £125.92	View offer

Best overall

KATSU Tools KATSU 151116

8.8/10about £69.99

View offer

Best value

KATSU Tools KATSU 151112

8.0/10about £49.99

View offer

Alternative

Clarke Clarke ECP15A1

7.0/10about £125.92

View offer

On this page

1.A butt is not a stream
2.Beside the tank, not in it
3.Leaves, grit, and a clean-water pump
4.Top-up from the tap, and bans

A butt is not a stream

Roof water already in a butt is stored rain. In England, taking more than about 20 cubic metres a day from a river, stream, lake, pond, or groundwater is likely to need an Environment Agency abstraction licence. A closed butt fed by downpipes is not that act. A pond linked to a watercourse can be. Scotland and Northern Ireland set their own thresholds. If the pump will sit on environmental water rather than a roof tank, check the licence before you shop. This page stays with stored rain. It does not design a river intake, and it does not invent a hosepipe-ban exemption. Read the live notice from your water company.

Beside the tank, not in it

A surface centrifugal in this set is not a submersible. Pedrollo states IP X4: splash protection, a cover beside the butt, not a seat in the water. Place the pump low and close so the real suction lift stays inside the stated ceiling, 8 m on the KATSU pair and 7 m on the Pedrollo rows, after hose rise. Fit a foot valve and strainer in the butt. Keep the inlet underwater while the tank still has water. A pump on a tall stand above a nearly empty butt pulls air. Both KATSU models say they are not self-priming, so fill the casing before the first start and after any drain-back. A surface pump fits when you will prime, the lift is short, and you want the pump outside for service. If you refuse to prime, a submersible is the other tool, and it sits outside this folder.

Testsieger

KATSU Tools KATSU 151116

8.8/10about £69.99

View offer

Leaves, grit, and a clean-water pump

Roof water carries leaves, moss, and grit from tiles. KATSU and Pedrollo listings limit the pump to clean water without abrasive particles. The cheaper KATSU notes warn that small articles damage the seal. A coarse strainer on the suction is the first filter, not a free pass to pump silty sludge. If the butt smells of silt every time you stir it, a clean-water peripheral is the wrong tool. Look at a dirty-water design instead of burning a seal on day three. Match the listing to the hose job after the water passes that test. For pressure on a single hose from a clean butt, the KATSU peripheral pattern, 35–45 L/min at 35–45 m stated, is the usual shape, with the 151116 as the stronger settled score and the 151112 as the budget warning. For emptying or transferring a large volume over a short rise, the Clarke ECP15A1’s 239 L/min and 2–14 m band is the volume tool, if you accept that clean water is unanswered on that extract. Stainless Pedrollo rows want a shelter and a curve, not a damp path in the open. None of these pumps is proved self-priming in the saved files.

Top-up from the tap, and bans

A rain-only butt is not a mains booster. The picture changes when a garden tap can fill the same tank or a tee joins the drinking-water pipe. In England and Wales, the Water Supply (Water Fittings) Regulations 1999, regulation 5, require notice before a pump over 12 litres per minute connects to a supply pipe, and before a non-hand garden watering system. Hose union taps need backflow protection matched to the risk. Ask the water company or a competent plumber when mains water can reach the butt. Hosepipe bans are temporary local rules. Read the current notice. Do not assume a rainwater pump is always exempt. A 30 mA RCD, a fully unwound lead, and a drain before frost still apply. When the source is roof water, the pump sits beside a clean butt, and the casing is full, a surface centrifugal can feed a hose. If any of those fail, fix the layout before you buy a dearer ASIN.

Common questions

Can I pump a water butt without an abstraction licence?

Stored roof water in a butt is not the same as abstracting from a river or groundwater. England’s roughly 20 m³/day test applies to environmental sources. Confirm if your tank is fed only by roof water.

Should the pump sit in the butt or beside it?

Beside it, under cover. These are surface pumps. IP X4 is splash protection, not immersion.

What if the butt is almost empty and the pump is on a stand?

Suction pull becomes air. Lower the pump, shorten the hose, keep the strainer submerged, or wait until the butt refills.

Will roof water with leaves wreck a clean-water pump?

It can, once grit reaches the seal. Strain first. If the water stays silty, choose a dirty-water pump instead.

Do I still have to prime?

Yes for the KATSU pair, which say they are not self-priming. Treat blank answers on other listings the same way unless the seller clearly claims self-priming.

Can I top the butt up from a garden tap?

That can create a backflow and fittings question. Keep rain-only if you can. If mains water can enter the tank, get proper advice before adding a pump.

Does a hosepipe ban automatically ban a rainwater pump?

Not automatically. Read your water company’s current notice. Do not invent a national exemption from this page.

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