How to use a Nilfisk pressure washer
Updated: 21.10.2026
You have a Nilfisk pressure washer on the patio and you want the first wash done without a dry pump, a ladder or a frozen start. The order is water through the gun first, the motor second, then a shut-down that drains the machine before a frost. This guide follows Nilfisk’s own sequence for the corded machines in the [Nilfisk pressure washer comparison](/hub/compressors/nilfisk-pressure-washer), not a switch-on-then-squeeze article. The steps come from the maker’s tutorial and manuals, plus Electrical Safety First and the HSE. We did not run the machines.
You have a Nilfisk pressure washer on the patio and you want the first wash done without a dry pump, a ladder or a frozen start.
You have a Nilfisk pressure washer on the patio and you want the first wash done without a dry pump, a ladder or a frozen start. The order is water through the gun first, the motor second, then a shut-down that drains the machine before a frost. This guide follows Nilfisk’s own sequence for the corded machines in the Nilfisk pressure washer comparison, not a switch-on-then-squeeze article. The steps come from the maker’s tutorial and manuals, plus Electrical Safety First and the HSE. We did not run the machines.
Our top picks
| Badge | Product | Motor | Hose length | Weight | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Nilfisk Nilfisk Core 125 | 1400 W | 5 m | 7.1 kg | 9.0 | about £115.99 | View offer |
| Alternative |  Nilfisk Nilfisk Excellent 160 | Title 2300 W; bullet 2100 W induction | 10 m | 23.6 kg | 6.7 | about £310 | View offer |
| Best value |  Nilfisk Nilfisk Core 150 | 2000 W | 10 m | 11.2 kg | 8.0 | about £202.79 | View offer |
On this page
Connect water and clear the air before you switch on
Fit the inlet filter, then a garden hose, and open the tap before you touch the switch. Nilfisk’s consumer instructions say to hold the lance and let water run until the air has gone, and only then to start the motor. Switching on and then pulling the trigger can run the pump dry. If the machine hunts at once, remove an Aquastop and try a plain connector before you blame the pump. Keep inlet water at or below 40 °C. A hose dropped into a dirty bucket can be a high fluid category under the Water Supply (Water Fittings) Regulations 1999, and the water company decides. Hose length and current for the model you bought are on the Nilfisk pressure washer buying guide.
Plug in, test the RCD, then wash
Use an outdoor socket with an RCD. The HSE says an RCD used against shock should be 30 mA, and that you should use the test button rather than bypass a trip. Electrical Safety First wants a UK 3-pin plug, and says not to wash in the rain or from a ladder. The Excellent 160 shop page specifies 13 A at 230–240 V. The Core 125 says 5.8 A and the Core 150 says 10 A. A coiled extension is a poor supply for 13 A. Prefer no extension; if you use one, unwind a single outdoor-rated lead. Keep the jet off people, animals, live equipment and the machine itself, and do not treat IPX5 as permission to wash in the rain. Stop if you smell burning, if the RCD trips again, or if the lead is damaged. Distances for slabs and timber are on the Nilfisk pressure washer for a patio page.
Switch off, release pressure, drain for frost
If you leave the machine for about five minutes, switch it off rather than leave the motor hunting against a closed gun. When you finish, release the trigger, turn the tap off, and squeeze the gun again to empty the line. Unplug, empty the machine of water, and store it frost-free. If the unit has already frozen, do not switch it on to see if it goes. Bring it indoors, wait until it has thawed, then purge water through the gun before any restart. A split hose or a frozen pump is a Nilfisk service job. Brand choice does not change that shut-down, including on the Nilfisk vs Kärcher pressure washer page.
When the machine hunts, leaks or will not start
Pulsing pressure is often air, a starved inlet or a blocked nozzle, not a reason to open the pump. Run water with the motor off until the spray is steady, check the inlet filter, and clear the nozzle with the cleaning needle. Put an Aquastop back only after a plain hose has run cleanly. While the warranty applies, a leaking gun, a split high-pressure hose or a damaged lead goes back to the seller or to Nilfisk. Do not tape the cord or strip the gun. A socket that keeps tripping, or a lead that smells hot, is an electrician’s job. Do not bridge the RCD to finish the wash.
Common questions
Do I turn the motor on before water comes out of the gun?
No. Open the tap, hold the lance and let water run until the air has left, and only then switch the motor on. That is Nilfisk’s order for the first fill. Switching on and then squeezing the trigger can run the pump dry.
Can I use an Aquastop hose connector?
You can try. Nilfisk’s tutorial says an Aquastop can restrict flow. If the jet pulses, remove it and use a plain fitting of about half an inch or wider. Put it back only if the machine then runs steadily.
How do I store it before a frost?
Switch off, unplug, release the pressure in the lance, and empty the machine of water. Store it where it will not freeze. Frost damage sits outside the guarantee in the longer consumer manual family.
Can I start it if it has been frozen?
Leave it switched off. Bring it into the warm until the pump and the hose have thawed, run water through the gun with the motor off, and only then start. If it still will not prime after that thaw, that is a service call.
Is a coiled extension reel safe for the Excellent 160?
It is a poor supply. The Excellent 160 shop page specifies 13 A, and a lead left coiled can overheat. Prefer the outdoor RCD socket. If you use a lead, Nilfisk Outlet’s rule of thumb is one 13 A cable, no longer than 20 m, fully unwound. The Core 125 is a lighter load and still wants that socket.
The gun leaks. Do I take it apart?
No. A leaking gun, a split high-pressure hose or a damaged mains lead goes back to the seller or to Nilfisk while the warranty applies. Clear a blocked nozzle with the needle after the motor is off. Call an electrician if the socket will not reset. Do not jet from a ladder.
Related pages
Sources
Public UK sources from the research digest. amazon.co.uk listings and Nilfisk shop prices checked on 19 October 2026.
- Nilfisk collection: high-pressure washers (retrieved 19 October 2026)
- Nilfisk Core 125-5 UK (retrieved 19 October 2026)
- Nilfisk Core 150-10 PowerControl (retrieved 19 October 2026)
- Nilfisk Excellent 160 (retrieved 19 October 2026)
- Electrical Safety First: pressure washers (retrieved 19 October 2026)
- HSE: electrical equipment and RCDs (retrieved 19 October 2026)
- GOV.UK: Electrical Equipment (Safety) Regulations 2016 (retrieved 19 October 2026)
- legislation.gov.uk: Water Supply (Water Fittings) Regulations 1999 (retrieved 19 October 2026)
- BSI: BS EN 60335-2-79:2012 high-pressure cleaners (retrieved 19 October 2026)
- amazon.co.uk: Nilfisk listings in this set (retrieved 19 October 2026)