How to install a deep well pump
Updated: 22 October 2026
Installing a deep well pump is about how it hangs, how the column stays up, and where you stop wiring it yourself. Lowering it on its flex is how a weekend job burns a motor. The seven listings are in the [deep well pump comparison](/hub/garden-watering/deep-well-pump). Peter F., editor for DIY & tools, updated this on 22 October 2026. We did not install them. A qualifying purchase can earn a commission at no extra cost to you. If you are still choosing head or diameter, use the [deep well pump buying guide](/hub/garden-watering/deep-well-pump/sub/deep-well-pump-buying-guide) first.
Installing a deep well pump is about how it hangs, how the column stays up, and where you stop wiring it yourself. Lowering it on its flex is how a weekend job burns a motor.
Installing a deep well pump is about how it hangs, how the column stays up, and where you stop wiring it yourself. Lowering it on its flex is how a weekend job burns a motor. The seven listings are in the deep well pump comparison. Peter F., editor for DIY & tools, updated this on 22 October 2026. We did not install them. A qualifying purchase can earn a commission at no extra cost to you. If you are still choosing head or diameter, use the deep well pump buying guide first.
Our top picks
| Badge | Product | Cable in the file | Low-water stop | Starts an hour | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Draper Draper 98921 well pump | Not stated | Float | Not stated | 9.4 | about £124.13 | View offer |
| Alternative |  Generic IBO SDM 24 borehole pump | 1.5 m or 20 m | Not stated | 20 | 7.2 | about £227.95 | View offer |
| Best value |  Generic 3 inch SKM 60 m pump | 15 m or 20 m | Not stated | Not stated | 6.9 | about £180.45 | View offer |
On this page
Lower it on the pipe, not the flex
The delivery pipe holds the pump, and a separate safety rope is the backup. The motor cable does not carry the weight. Tie the cable to the pipe so it cannot rub, and leave the rope with a little slack so the pipe stays the main support. One United Kingdom Draper review found no obvious rope point that keeps the pump vertical. If the body might jam, use the borehole or wide well page. Do not make an underwater cable joint as a DIY splice. The SDM 24 and the STM 28 both say 20 metres and a plug in the title and also allow 1.5 metres in the technical data. You can only install the length that is in the box.
Hold the column and limit the starts
When a submersible stops, the column wants to fall back through the pump. A check valve on the discharge, close to the pump, holds that column. Waterpump.co.uk describes that valve as the way to stop short-cycling. If people will drink the water, fittings that touch it are a WRAS question, not a garden-hose question. A tiny vessel, or none, lets the pressure switch click every time a tap opens. Only two files here write a starts limit: the SDM 24 at 20 an hour, and the STM 28 at 30. Pedrollo’s 20-start figure belongs to that range, not to the Draper, the SKM pumps, the STM 24 or the Trotec. These are capacitor-start pumps, not an inverter drive, so a tiny vessel is not a substitute for draw-off.
Stay wet, and only as deep as the listing says
These pumps are cooled by the water around them. Running dry cooks the motor, and thermal protection, where it is even stated, is not a plan to empty the hole. The Draper includes a float so the pump can switch off as the level falls. One river review describes that float being tied up so the pump kept running. Do not copy that. On a borehole, where a float may have nowhere to swing, use a level probe or a dry-run device rather than strapping the float. The SDM 24 states 100 metres maximum immersion. The STM 28 states 80 metres. IP68 on a title is not permission to hang the pump at any depth. The STM 28’s title cable is 20 metres, which cannot place the pump at 80 metres even if the long lead arrives. Where the file is silent, do not invent a depth from the headline head.
Where you stop
Electrics are the hard stop. AES Rewinds closes its well-pump guide by pointing outdoor circuits at BS 7671 and RCD protection. That is their close, not an RCD type, and this page will not prescribe one. Several IBO titles say “with a plug” and do not say BS 1363. No listing here confirms a UK 13 A plug. The STM 28’s bullet says 9.7 A and the 4 inch SKM’s bullet says 10 A. Those are not casual extension-lead loads. The Trotec’s power-source line says Hand Power while the voltage line says 240 V and the horsepower field says 550 W. Do not wire from that conflict. A new circuit to a wellhead belongs to a competent electrician, certified to BS 7671. Do not cross-connect a private supply to the mains.
Common questions
What holds the pump if I must not use the cable?
The delivery pipe holds it, and a separate safety rope is the backup. Tie the motor cable to the pipe so it does not chafe, and do not let it carry the hanging weight. On the Draper, one UK review found no obvious rope point that keeps the pump vertical, so the tie still has to hold the body upright.
Where does the non-return valve go?
On the discharge, close to the pump, so the column does not fall back through the impellers when the motor stops. That is the short-cycling protection Waterpump.co.uk describes. If people will drink the water, the fittings are a WRAS question. A valve does not replace a pressure vessel.
Why does a tiny pressure vessel hurt the motor?
A very small vessel, or none, lets the switch start the pump whenever a little water leaves the pipe. The SDM 24 allows 20 starts an hour and the STM 28 allows 30. The other listings do not state a number, and Pedrollo’s 20-start figure belongs to that range, not to them.
The Draper has a float. Can I tie the float up?
No. The float is the low-water stop on that listing. One river review kept a pump running by tying the float up, and the file does not add another dry-run device. On a borehole where a float cannot swing, use a proper level or dry-run control.
What immersion depth is actually written down?
The SDM 24 states 100 metres maximum immersion. The STM 28 states 80 metres, IP68 and 35 °C. The SKM pumps state 35 °C and IP68 and do not state immersion. The Draper, the STM 24 and the Trotec do not state a depth. Do not read headline head as immersion.
Who wires a new circuit to the wellhead?
A competent electrician, with fixed wiring certified to BS 7671. This page does not specify an RCD type. Several titles mention a plug and none names BS 1363. The STM 28 at 9.7 A and the 4 inch SKM at 10 A are not casual extensions. Stop if the cable in the box is 1.5 metres or anyone will drink the water.
Related pages
Sources
Public UK sources from the research digest. Shelf prices, heads, flows and conflicts are from the amazon.co.uk saved listings in this category, not a live re-check on 21 October 2026.
- GOV.UK — check if you need a licence to abstract water (retrieved 21.10.2026)
- Water Resources Act 1991, section 198 (retrieved 21.10.2026)
- British Geological Survey — drilling legislation and obligations (retrieved 21.10.2026)
- Natural Resources Wales — water abstraction or impoundment licence (retrieved 21.10.2026)
- SEPA — abstraction under 10 cubic metres a day (retrieved 21.10.2026)
- DAERA — applying to abstract or impound water (retrieved 21.10.2026)
- AES Rewinds — choosing the right well pump (retrieved 21.10.2026)
- Drinking Water Inspectorate — single dwelling supplies (retrieved 21.10.2026)