Stihl RCA 20 Cordless Pressure Washer Review

Design and Features

• Comes with a carry case
• Works with a hose or provided 20-litre water bag
• Spray hose, soap dispenser and multi nozzle

The Stihl RCA 20 isn’t the first battery powered presure washer that I’ve reviewed, that’s the Karcher KHB 5. Good for its time, the KH5’s main problems were its size, short run time and long charge time; all things that the Stihl RCA 20 manages to avoid.

To keep the size down, the RCA 20 runs on Stihl’s 10.8V AS battery platform, which is home to a growing number of tools from the GTA 26 cordless pruner and the HSA 40 hedge trimmer. While the 10.8V system can’t deliver the power of Stihl’s 36V AK system, its tiny batteries are still capable and, most importantly, very light.

In fact, the Stihl RCA 20 weighs just 1.5kg, which is over 1kg less than the KH5. And, the RCA 20 is smaller and easier to hold, all valuable attributes both for carrying the pressure washer around and when using it.

This tool can be bought barebones (£149) if you have AS batteries that you can use already, or you can buy it with two batteries and an AL 1 charger for £50. It’s worth having two batteries for this pressure washer, as you’ll double the run time to around 30 minutes of continuous use, which will let you wash further than you might expect.

Batteries take 60 minutes to charge to 80% or 80 minutes to 100%; that’s much better than the KH5, which shipped with a slow charger that took 290 minutes to fully recharge the battery.

Stihl has thought of everything with the Stihl RCA 20, and it even ships with a handy carry bag that’s big enough for the pressure washer, charger, batteries and all of the accessories. Whether you keep the pressure washer at the back of your shed or you’re transporting it in the boot of your car, that bag is very useful.

You get the main accessories that you’d expect from a pressure washer, including a 4-in-1 nozzle that gives you rotary, fan-jet, narrow jet and watering modes.

The mode is selected by turning the nozzle, and lining up the relevant icon. It’s easy to do and it’s quick to change between spray patterns.

This nozzle can be attached straight to the RCA20 or you can use it with the spray lance extension that clips onto the front.

There’s also a separate detergent spray set, with a bottle that you fill with your choice of liquid detergent, which is then mixed with water. Again, this tool can be attached directly to the RCA 20 or to the end of the wand.

A dial on top of the detergent bottle is useful for adjusting the amount of spray you get.

A standard hose connector is provided underneath the pressure washer, so you can use it with mains water connected via your current hose pipe.

If you’re going somewhere without running water, then Stihl provides a 5m suction hose with filter, which you can drop into a bucket.

Stihl even provides a 20 litre water bag, which folds down and fits in the carry bag, so you can take water with you. There’s no difference in pressure between using a suction hose or mains powered hose: the pressure washer operates at 22 bar, with a maximum pressure of 24 bar.

Obviously, that’s a lot less than a typical pressure washer, where I’d expect 120 bar plus, but the Stihl RCA 20 is designed for smaller jobs.

It’s brilliantly simple to use. Once there’s a water supply, and the battery is connected, just slide the ambidextrous lock switch out of the way, and squeeze the trigger to start spraying water.

If you need to dial down the power, then there’s an Eco mode button at the back, which reduces pressure and increases the run time. There’s also a handy battery meter with three LEDs that extinguish one at a time to show you how much power is left.

Performance

• Struggles with tough dirt
• Good for lighter jobs
• Versatile spraying

I tested the Stihl RCA 20 with my usual job: cleaning my patio, which gets very dirty thanks to my three cats traipsing dirt across it. I started by spraying the patio with detergent, which foamed nicely. In this regard, I don’t see any difference between this pressure washer and the full-power Stihl RE 100 Plus Control.

I then used a combination of rotary and fan-jet to tackle the dirt. I got some of it, but it was slow going, and the Stihl RCA 20 couldn’t touch the deeper stains and struggled to remove them. Surface stains are fine, but I needed a more powerful pressure washer for the real grime.

I had a few gaps in the sand between the paving slabs that had allowed some weeds to grow. I found the Stihl RCA 20 more than capable of removing this growth, so that I could repoint the grout lines.

I then tackled the decking outside of my office. As noted in our guide on how to clean decking with a pressure washer, it’s important not to use too much power; in that regard, the Stihl RCA 20 is perfect.

First, I blasted out the moss growth that had accumulated between the decking planks. I found the narrow jet mode perfect for this.

I then used the flat spray to blast away the accumulated dirt, which the Stihl RCA 20 handled well.

To see how well it worked on other areas, I tackled the cedar cladding on my garden office, which had faded to a dull grey. As you can see from the shot below, there’s a clear contrast where I’ve cleaned, and where I haven’t, showing that this mini pressure washer can deal with some tougher jobs in the right conditions.

At the back of the garden I have some concrete steps leading up to the parking space. These get caked in mud, which washes down, and the RCA 20 was perfect for removing the mess.

For cleaning down a bike and washing dirt off of a dusty car, the Stihl RCA 20 is also perfect: not enough power to cause damage, but enough pressure to quickly wipe off typical dirt. The same is true for garden furniture.

One battery doesn’t give quite enough time to tackle most jobs, but with two batteries ready to go, 30 minutes of cleaning time let me wash down the front of my office with ease, and clean the decking in front of it. I also think that 30 minutes is enough to clean a few bikes and wash down a car.

Should you buy it?