Karcher Wet and Dry Vacuums: NT Series Compared, and What Changes on Water

The Karcher NT range runs from A$329 to over A$1,500, and the price difference is not about suction. It is about dust class, tank handling and whether the machine can be emptied without lifting it. Choosing on tank size alone is how sites end up with the wrong machine.

Read the model code before the price

In the NT range the numbers give capacity in litres, so NT 20/1 is a 20 litre single-motor machine. The letters matter more than the numbers: L and M denote dust class, which determines whether the machine suits the material you are picking up and whether the site will accept it.

Every NT in our range handles both wet and dry pickup, which is the appeal of the series. What changes between models is how you empty it, what filtration it carries, and whether it is practical to move a full tank.

Prices are Freshway catalogue prices as at 16 September 2026 and are subject to change. Confirm the current price, and whether GST applies, before quoting.

The NT range compared

The jump from A$659 to A$1,094 between the NT 48/1 and the NT 30/1 Tact L is not a capacity increase — it is the opposite. You are paying for automatic filter cleaning and L-class filtration, which means the machine can run longer between filter cleans and can be used on dust where a standard machine is not appropriate.

Wet pickup: the filter question that catches everyone out

The most common question we are asked about these machines is whether the filter stays in when you vacuum water. The answer is that it depends on the machine, and getting it wrong is expensive.

• Wet pickup uses a different filter configuration from dry pickup on most machines. Many NT models require the cartridge or main filter to be removed for wet work, leaving a foam or wet filter in place.
• The manual for your specific model states which. NT models differ, and assuming one configuration applies across the range is how filters get destroyed.
• Operating with the wrong filter in place typically means the filter media becomes saturated, loses structure, and in some cases allows water into the turbine — which is a repair rather than a filter replacement.

We stock the Karcher parts and accessories for the NT range including filters and cartridges, and if you are unsure which configuration applies to your machine, send us the model code and we will confirm it rather than guess.

Dust class: standard, L and M

Dust class is the specification most often overlooked when a machine is bought on price, and it is the one with compliance consequences.

Automatic filter cleaning matters here. Without it, filtration performance degrades as the filter loads and the operator has to stop and clean it manually — which is exactly when pre-separators get removed and machines get used outside specification. Tact models clean the filter on a cycle, keeping both suction and filtration closer to specification for longer.

If the site is a construction or woodworking environment, check what class is specified before ordering. The SafeWork NSW guidance on respirable crystalline silica is a useful starting point for what those requirements mean in practice.

Wet or dry: where the line actually falls

Every NT in this range does both, but not equally well and not without reconfiguration. The practical distinction is what the machine does most of the time:

• Mostly dry, occasionally wet — any NT model works. Keep the correct wet filter configuration with the machine so it is there when needed.
• Mostly wet — a larger tank and a drain or pump arrangement changes the job more than suction does. Emptying 48 litres by lifting is a different task from emptying it through a drain.
• Flood recovery — tank capacity is the limiting factor, not power. A A$1,519 NT 70/2 running for an hour moves more water than any number of smaller machines being emptied repeatedly.

Maintenance: what to clean and when

NT machines fail for predictable reasons, and all of them are filter-related.

1. After every wet pickup — empty the tank, wash and dry the wet filter, and leave the tank open to dry. Damp tanks produce odour and corrode.
2. Weekly on dry duty — check the cartridge filter and the float assembly, which is what prevents water reaching the turbine.
3. On filter loading — replace paper filters rather than reusing them. A loaded filter reduces both suction and filtration, and the drop is gradual enough to go unnoticed.
4. Before storage — store with a clean, dry filter, and buy one spare so a cleaning cycle never takes the machine out of service.

Our wet and dry vacuums range and the Karcher brand range cover both machines and consumables, and the service team handles turbine and motor repairs.

Matching the machine to the job

Frequently asked questions

Do you leave the filter in a wet dry vac when vacuuming water?

It depends on the model. Most Karcher NT machines use a different filter configuration for wet pickup and require the dry cartridge filter to be removed before water is collected. Check the manual for your specific model — assuming one NT behaves like another is the most common cause of destroyed filters and water reaching the turbine.

Are Kärcher wet and dry vacuums any good?

Yes. The NT range is the reference point in professional wet and dry vacuums, and the depth of the range — from a 20 litre single-motor machine to 70 litre twin-motor units and M-class models — is the reason. Parts and consumables are continuously available, which matters more over a machine's life than the purchase price.

What is the best wet and dry vacuum cleaner in Australia?

It depends on what the machine picks up. Mixed general work suits the NT 20/1 or NT 30/1. Ongoing dust in trade use suits a Tact model with automatic filter cleaning. Sites with medium-hazard dust require an M-class machine such as the NT 30/1 Tact TE M.

What is the best Kärcher wet and dry vacuum?

For most commercial cleaning work, the NT 27/1 is the practical middle of the range. For trade work with continuous dust, the NT 30/1 Tact L is the step that changes how often you have to stop and clean a filter. For bulk liquid, the NT 70/2.

Can I use a wet and dry vacuum without a bag?

Yes for wet pickup, and for dry pickup where the model is designed to run bagless with a cartridge filter. Bags are not required on the NT range for wet work, but running bagless on fine dry dust loads the cartridge faster and increases the cleaning interval. It does not damage the machine provided the filter is maintained.

References

• SafeWork NSW — guidance on respirable crystalline silica and hazard controls.
• SafeWork NSW — noise at work.