Which pressure washer brand is most reliable?

We investigated the performance and reliability of some of the most popular pressure washer brands including Bosch, Nilfisk and Karcher.

In our unique gardening product survey, we ask more than 7,635 Which? members and members of the public if they’re happy with their pressure washers and if they’ve experienced problems, so you can see which brands are worth the money.

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Which pressure washer brands develop the fewest faults?

This table summarises what we found about how quickly pressure washer brands develop faults or break down, based on ones bought in the past five years.

As you can see, pressure washer brands differ when it comes to chances of developing faults – the best saw only 11% of models develop a fault in the first five years, for the worst it was more than 22%

Join Which? to get access to the table below, plus all our Best Buys and pressure washer reviews. We’ve tested pressure washers from brands including Karcher, Bosch and Nilfisk, but only the very best make a Best Buy.

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To see which models performed best in our rigorous lab tests, head over to our best pressure washer page.

Which pressure washer brands do owners recommend?

We've crunched the numbers to calculate customer scores for some of the most popular brands to reveal which owners feel happy with and which they would recommend to a friend.

Join Which? to get access to the table below, plus all our Best Buys and pressure washer reviews. We’ve tested pressure washers from brands including Karcher, Bosch and Nilfisk, but only the very best make a Best Buy.

Top three common pressure washer faults

1. Loss of pressure (17%) There can be a number of problems that cause this, such as a blocked nozzle or water inlet, inadequate water supply, or air in the inlet water supply hose or the pump. Follow the steps below to help you diagnose the root cause.
2. Leaking within the pressure washer (16%) This is often due to water freezing and then expanding inside the washer. Make sure it's drained and stored in a frost-free place after use.
3. Motor failed (9%) Frozen and cracked pump parts are the chief suspect here, but another culprit could be running the pump without the water flowing, or ignoring other problems that cause the pressure washer to run incorrectly. Store the pressure washer in a frost-free place, such as a cupboard in the house, and ensure the water is turned on and at adequate pressure before running the pump.

How to fix a loss of pressure

Loss of pressure is the biggest issue for pressure washers. There could be various reasons causing this, but before taking it to a repair shop or replacing it, consider the following:

• If the pressure is pulsing, check the water supply is fully turned on and the hose is not kinked, which could stall pressure.
• Inspect for leaks, holes or tears in your garden hose. If you find any, plug the holes or replace the hose.
• Clean the water filter. To get rid of the air, run the pressure washer with an open spray handle and nozzle at low pressure until regular working pressure resumes. If the pressure is steady but low, it can indicate a worn stop/start valve – squeeze the trigger five times in quick succession to get it working again.
• Check for blockages in the nozzles by shining a torch through them. If you can't see through, use a small tool, such as a toothpick, to remove any clogs.
• If you rely on one nozzle the most, it may have worn out. Attach a nozzle you use the least to see if the pressure increases. If it does, it may just mean it's time to replace your other one.  

Which pressure washer brands offer the best guarantees?

Most pressure washer brands offer product guarantees of at least a year, but a handful of popular brands offer longer cover, including:

• Karcher - two-year guarantee for domestic use, which can be extended to five years if registered within 28 days of purchase.
• Nilfisk - two-year guarantee for machines and accessories and a one-year warranty for repairs and spare parts.
• Bosch - two-year guarantee, rising to three years if the garden appliance is registered with Bosch.
• Husqvarna -two-year guarantee after registration; battery warranty is handled separately.

How we calculate the best and worst brands

Which? has a wealth of information on the UK's favourite garden tool brands. Every two years, we ask Which? members and the general public to tell us about the garden products they own, from how likely they would be to recommend a brand to whether they experienced any faults with it. This year, 7,635 people told us about their products. We calculate a brand's customer score based on the results of our biennial survey.

Our product experience surveys and extensive lab tests mean we can recommend the best pressure washer you should buy.

 Ready to pick one? See our round-up of the best pressure washers.