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Cordless dirty water pump vs mains

Updated: 22 October 2026

The nearest socket is a wet extension lead you do not trust. Cordless wins when there is no safe 230 V supply and the job is short. Mains wins when the volume or the lift is a cellar, a large pond, or anything you cannot finish on a battery you already own. The Solo price is not a working kit, and about 0.5 bar will not run a sprinkler. The [Einhell dirty water pump comparison](/hub/garden-watering/einhell-dirty-water-pump) shows both kinds of listing. Peter F. used Einhell UK pages and amazon.co.uk prices from 19 October 2026. This is not a lab test. A qualifying purchase can earn a commission at no extra cost to you.

The nearest socket is a wet extension lead you do not trust. Cordless wins when there is no safe 230 V supply and the job is short.

Our top picks

Einhell Einhell GE-DP 18/25 LL Li

Best overall

Einhell Einhell GE-DP 18/25 LL Li
8.3/10about £89.99
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Einhell Einhell GC-DP 3325

Best value

Einhell Einhell GC-DP 3325
8.2/10about £37.97
View offer
Einhell Einhell GC-DP 7835

Rank 3

Einhell Einhell GC-DP 7835
8.4/10about £50.50
View offer
On this page
  1. 1.What each power source is for
  2. 2.The two Einhell Solo models
  3. 3.What cordless will not do
  4. 4.The £26 pumps

What each power source is for

A mains dirty-water pump in this set is a 230 V submersible for intermittent volume. The GC-DP 3325 starts at £37.97 with 6 m of head. The GC-DP 7835 is £50.50 with 8 m and 35 mm. They need a BS 1363 plug and 30 mA RCD protection under BS 7671 regulation 411.3.3. A flooded consumer unit is not a socket. An 18 V body is for a place the lead should not go, if the job ends quickly. These cordless pumps publish about 5 m and 0.5 bar. That empties a cooled tub or a small chamber. It will not replace an 8 m mains pump. The charger still plugs into the mains.

The two Einhell Solo models

Both cordless Einhells in this set are Solo. The box is the pump and a universal adapter. Battery and charger are flagged “No”. The GE-DP 18/25 LL Li at £89.99 is the 2-in-1 body: about 7,000 L/h, 5 m, 25 mm, and a 1 mm residual claim on clear water, with 4.6 from 180 reviews. The GE-DP 18/25 Li at £99.98 is the non-flat body: about 7,500 L/h, the same 5 m class, residual water around 35 mm, and 4.4 from 163 reviews. The higher price does not buy more head. Neither Solo includes a hose. Add the price of packs you do not already own before you compare £89.99 with a £37.97 mains pump.
Einhell Einhell GE-DP 18/25 LL Li

Testsieger

Einhell Einhell GE-DP 18/25 LL Li
8.3/10about £89.99
View offer

What cordless will not do

It will not water the lawn. Einhell says garden watering with the GE-DP 18/25 Li is only limited, which matches 0.5 bar. A sprinkler is a surface-pump job. Particle size for that kind of buy sits on the buying guide. It will not clear an all-day flood. Head stops at about 5 m, and the battery is finite. If the room is flooded and the sockets are wet, the basement page and an electrician come before either pump.

The £26 pumps

Two listings at £25.99 look like the same idea and are not. The BTRUI is about 600 g and still needs an 18 V battery. The TPDL is about 200 g, prints both 12 V and Einhell 18 V, and describes no float. They are transfer toys, not a GE-DP 18/25 LL and not a cellar pump. For a cooled tub and packs you already own, buy the LL Solo if flat suction matters, or a mains GC-DP 3325 if an RCD socket is there. For a cellar or a big pond, buy mains.

Common questions

When is cordless the better buy?
When the socket is missing or unsafe and the job is a tub or a small chamber you can finish on packs you already own. The GE-DP 18/25 LL Li at £89.99 is the usual body, with a 1 mm claim on clear water. It is the worse buy for a cellar, or if you would have to buy the batteries from scratch. Mains wins when a 30 mA RCD socket is there and the volume is large.
What is not in the Solo box?
The battery, the charger and the hose. Both the £89.99 LL and the £99.98 non-flat model list a pump and a universal adapter. The comparison rows mark the battery as absent. Reviewers suggest a second pack if you have more than one tub to empty. Add the packs to the price before you decide the cordless body is only a little dearer than a mains pump.
Will it empty a hot tub on one battery?
Reviewers say one 4 Ah pack can finish a Lay-Z-Spa, and that the same pack is tight if a second job follows. Einhell does not print a runtime in minutes on the UK Solo pages, so treat that as a review theme rather than a timed test. Cool the tub below 35 °C first. The LL model is the one that claims to leave less water, on a hard base.
Can I water the garden with it?
Only in a very limited way. Einhell says so on the GE-DP 18/25 Li page, and the pressure is about 0.5 bar. That will not run a sprinkler. Submersible dirty-water pumps move volume. Surface pumps make the pressure a hose nozzle wants. If watering is the job, this is the wrong pair of pumps. If emptying is the job, the low pressure is not a fault.
What if I do not already own Einhell batteries?
Buy a mains pump if you have an RCD socket. The GC-DP 3325 at £37.97 plus a hose will empty a cooled tub. A Solo body at £89.99 or £99.98 still needs at least one Power X-Change pack and a charger. Cordless is poor value when you are entering the battery system only for this job. It is reasonable value when the packs already run your other Einhell tools.

Related pages

Best Einhell dirty water pump

How to use a dirty water pump

Einhell dirty water pump

Pump out a flooded basement in the UK: when to stop

Einhell dirty water pump guide: particle size first

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)