Product Test: Rozone’s Rowasher

Product Test: Rozone’s Rowasher

John Rayment from Rayments Garage, situated just outside of Cambridge, sees what washes with the Rowasher.

We are a small family run garage and recently PMM gave us the chance to test the static Rowasher. I have used a much older version of this in the past but it has undergone a massive transformation from the old unit and I was interested in trying the newer one.

Product Test: Rozone's Rowasher

We already have a parts washer and it does its job okay but I always dread the time to replace the solvent in it as I always end up with a messy floor and the issue of disposing of the old dirty fluid. We have also tried the subscription option where someone does the dirty work but that worked out too expensive for us to justify.

So the Rowasher was delivered and installed by Rozone although there was not too much to set up as the unit comes in few parts and goes together very easily, a lot of thought having gone into the new design. With the fluid poured in and the unit switched on, we were shown how to use it and given an explanation of the idea behind the washer. This is what really makes the Rowasher so much different to the norm. It is not solvent-based.

Product Test: Rozone's Rowasher

Firstly, the machine is about the same size as our old parts washer – same height and bowl size and it’s easy on the eye. The machine is made of tough plastic and looks robust.

Water-based detergent

Secondly, the fluid/cleaner. The system is filled with a water-based detergent making it safe and environmentally friendly. The fluid is heated to between 37˚C and 42°C and then the magic bit happens. There is a filter mat that has microbes in it that are released into the fluid and these little organisms live in the fluid and feed on the oil and grease that are washed out. Larger particles are trapped in the filtering mat.

Product Test: Rozone's Rowasher

So that’s the science behind the unit and due to this it makes it safe to use.

Once a month, the filter is replaced and this aims to top up the microbes/eaters in the fluid and keeps the fluid fairly clean. We have had the machine for a few months now and the fluid has only darkened very slightly in this time.

Now to using the machine. It is very straight forward – push a button to start, push and hold the button to switch it off. There are two lights on the control panel (green and amber) and these tell you the state of the machine. The instruction manual that comes with the machine is very clear on what they mean and then what action may be required.

You can use the brush with the fluid running through it and there is a hose that you can use on bigger items or to rinse when cleaning – this helps with the really messy parts or bigger parts. The fluid runs through the big sink through a metal plug filter and which can be easily removed to clear out the large debris. The fluid then flows through the filter mat and back into the sump. The flow rate is very good but this can sometimes cause splashing outside of the unit, hence the cardboard we have around the machine.

The fluid is always warm which is novel. It is this that keeps the organisms alive and doing their job.

We, like many garages today, are having staffing issues. We have had a few technicians help us out when really busy and they also have been impressed with the machine’s look and ability to do its job.

So far we haven’t found anything that we couldn’t get clean. From engine sumps – when replacing an oil strainer, oil filter housings, EGR valves and so many other items. Another good use we found is the cleaning of rubber pipes and hose (such as intercooler pipes) as there is no solvent is in the fluid, we don’t need to worry about the effects that it may have on the material we are cleaning. All our measuring jugs, draining trays and anything else I can find have never been cleaner as I am quick to use the machine as much as I can. The detergent also smells good. We haven’t needed to yet, but when it comes to cleaning the machine, it is an easy process with all parts being easy to get to and move.

There is very little not to like about the machine. As I have said before, we occasionally splash over the side of the machine but the ease of use, low maintenance and the fact no solvents are used, far outweigh the negatives.


The Rowasher is definitely worth considering if you’re looking at replacing an old parts cleaner or thinking of adding one to your workshop. It’s very easy to use, keep clean and maintain. Changing the filter monthly couldn’t be easier (and Rozone even supplies you with a wall chart so you can keep an eye on when the change is due as we all know how time flies by).

The literature/instructions that come with it explain the use of the micro-organisms far better than I can – the science bit. But all I need to know is that because of these ‘eaters’, the cleaner does its job well, the fluid stays clean and is environmentally friendly which is a big plus in today’s climate.

In essence, for the time that we have had the cleaner, I have been very impressed with it (and so have others) and I would definitely recommend it to workshops. I understand there are different models so they appear to have a machine to suit any size of job/workshop. The changes made from the early model are very positive ones and ultimately the bioremediating process is fascinating.

Finally, if you’re local to us and were considering buying one, I would be happy to show it off – any excuse to use it!

Want to know more? For more information click here.

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