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Pump out a flooded basement in the UK

Updated: 22 October 2026

The cellar floor is under water and a submersible from amazon.co.uk looks like the quick way out. Pumping out a flooded basement in the UK can be a one-off job for a portable dirty-water pump, or it can be the wrong tool entirely. The difference is electricity, depth, and whether this is the first time or the fifth winter. The [Einhell dirty water pump comparison](/hub/garden-watering/einhell-dirty-water-pump) lists the twelve pumps. Peter F. used GOV.UK flood guidance, Electrical Safety First and amazon.co.uk listings from 19 October 2026. There is no lab test. A qualifying purchase can earn a commission at no extra cost to you.

The cellar floor is under water and a submersible from amazon.co.uk looks like the quick way out.

Our top picks

Einhell Einhell GC-DP 3325

Best overall

Einhell Einhell GC-DP 3325
8.2/10about £37.97
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Einhell Einhell GC-DP 9035 N

Alternative

Einhell Einhell GC-DP 9035 N
8.0/10about £70.99
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Einhell Einhell GC-DP 7835

Rank 3

Einhell Einhell GC-DP 7835
8.4/10about £50.50
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On this page
  1. 1.Power and depth first
  2. 2.What a consumer dirty-water pump can shift
  3. 3.Where the water is allowed to go
  4. 4.One flood or every winter

Power and depth first

Switch the power off before you wade in to look. GOV.UK’s flood-adaptation guidance tells you to get an electrician to check the installation before you use an electric pump, because floodwater and a live circuit are a worse problem than a wet floor. If the consumer unit, the sockets or the cable routes have been under water, a new pump does not make them usable. Once a dry socket is confirmed, use 30 mA RCD protection. A two-pin plug is a return. Do not cut it off. Depth is the second stop. GOV.UK says that about a metre of water inside is a reason to speak to a structural engineer, and that large floods can take days. You also wait until the water outside is lower than the water inside, or you pump against water that will come straight back.

What a consumer dirty-water pump can shift

If the water is shallow, the power is confirmed safe, and this is a one-off, a mains dirty-water pump can move it. Rainwater that has crossed a cellar floor and picked up silt is dirty water in the ordinary sense: sandy, muddy, with bits in it. It is not sewage, and an amazon.co.uk sewage browse path does not make these ASINs sewage pumps. For silt and small debris, 35 mm is the particle band on the GC-DP 7835, the GC-DP 9035 N and some FOTING listings. Head is the height from the water to the discharge, plus the hose. The GC-DP 7835 publishes 8 m maximum, and that is not 8 m of full flow. Toolstation says the GC-DP 7835 is not a permanent installation and not for a fish pond. Particle size and head, as buying tests, are on the buying guide.
Einhell Einhell GC-DP 3325

Testsieger

Einhell Einhell GC-DP 3325
8.2/10about £37.97
View offer

Where the water is allowed to go

The hose has to end somewhere legal. GOV.UK tells you not to flood someone else. A drain, a sewer or a watercourse may need a permit or consent. If you are unsure, stop and check with the authority GOV.UK points you to before you empty a cellar into it. Do not connect dirty floodwater to drinking-water pipework. The hose is not in these boxes.

One flood or every winter

One flood, after a burst and a safe supply, is what a portable mains pump is for. You do not leave it locked in continuous mode overnight. A cellar that fills again next month is a different building problem. Groundwater, a failed drain or a high water table will beat a weekend pump. Buying a second GC-DP 7835 does not create that system. Toolstation’s exclusion of permanent installation is the retail version of the same limit. Cordless is the wrong scale for a full cellar. Why that body is the wrong scale is on mains versus cordless.

Common questions

Should I switch the power off first?
Yes. Treat a flooded cellar as electrically unsafe until an electrician has checked it. GOV.UK says to get that check before you use an electric pump. A portable pump on an extension lead does not make a wet consumer unit acceptable. Once you have a dry, RCD-protected socket, keep the lead uncoiled and unplug the pump before you clear a blockage. If you cannot isolate the supply, stay out.
Can I pump into the drain?
Only if that discharge is allowed. GOV.UK warns that a permit may be required, and that you must not flood other people. A road gulley, a foul drain and a watercourse are not interchangeable. If you do not know which you have, check before you pump. Sending a cellar of silt into the wrong pipe can block it or push water onto a neighbour.
Will a cordless pump clear a cellar?
Not a full one. The Einhell Solo bodies are about 5 m and 0.5 bar, and the battery is extra. Reviewers describe one 4 Ah pack as a hot-tub job rather than a room you can leave running. A mini 18 V pump around 200 g is smaller again. Use a mains pump on a checked RCD socket for a one-off shallow flood. If there is no safe socket, fix the supply first.
The water is a metre deep. Do I carry on?
No. GOV.UK treats about a metre of internal water as a reason to speak to a structural engineer. Large floods can take days, and you should not pump hard while the water outside is still higher. A 5 m immersion figure on the GC-DP 9035 N is a product limit, not permission to work in water that deep. Keep petrol pumps out of the room.
What if it floods again next month?
A second flood means the portable pump was a mop, not a cure. Groundwater or a failed drain will return. A designed sump, with a pump chosen for repeated duty, is the usual next step. Toolstation already says the GC-DP 7835 is not for permanent installation. Do not store a consumer pump in the hole and call it automatic.

Related pages

How to use a dirty water pump

Einhell dirty water pump

Best Einhell dirty water pump: one listing per job

Einhell dirty water pump guide: particle size first

Cordless dirty water pump vs mains: what Solo misses

Sources

Public UK sources used for RCD protection, product safety marking and flood pumping limits. Manufacturer pages used for head, flow, particle size and the 35 °C limit. Listing prices, stars and review counts are the amazon.co.uk lines saved on 19 October 2026. This is not a lab test.

  1. Einhell UK — dirty water pumps (retrieved 19.10.2026)
  2. Einhell UK — GC-DP 7835 (retrieved 19.10.2026)
  3. Einhell UK — GE-DP 18/25 Li Solo (retrieved 19.10.2026)
  4. Einhell UK — GE-DP 18/25 LL Li Solo (retrieved 19.10.2026)
  5. Toolstation — Einhell GC-DP 7835 (retrieved 19.10.2026)
  6. Electrical Safety First — garden electrics (retrieved 19.10.2026)
  7. IET Wiring Matters — BS 7671 411.3.3 (retrieved 19.10.2026)
  8. GOV.UK — Electrical Equipment (Safety) Regulations 2016 (retrieved 19.10.2026)
  9. GOV.UK — adapting a home to flooding (retrieved 19.10.2026)