The filter on a pressure washer is a critical component that serves to protect the pump and other internal parts by preventing debris from entering the system. As pressure washers operate at high pressures ranging from 1000 to over 4000 PSI, even small particles can damage the inner workings if allowed to pass through. The filter acts as a barrier to catch dirt, sand, pebbles, and other contaminants in the water supply before they reach sensitive components. Knowing the function and maintenance needs of your pressure washer’s filter is important for optimal performance and longevity.
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Types of Pressure Washer Filters
There are two main types of filters used on most pressure washers:
Inline Filter
This is the most common type of filter found on electric and gas pressure washers. Inline filters are tubular units fitted between the water inlet and the pump. Water passes through a screen inside the chamber to trap particles before exiting to the high-pressure pump. These are easy to inspect and clean by unscrewing the housing and rinsing the filter screen. However, inline filters have limited filtering capacity before needing replacement.
Cartridge Filter
Cartridge filters provide finer filtration and higher dirt-holding capacity. They use a pleated cartridge element inside a sealed housing mounted on the pressure washer frame or engine. Water flows from the outside to the inside of the cartridge, trapping small particles across a large surface area. Cartridge filters require less frequent cleaning but need replacing once saturated with contaminants. They are common on larger commercial pressure washers.
Filter Locations
The filter may be positioned at the water inlet or on the pressure washer’s frame depending on the model. Here are some common filter locations:
Garden Hose Inlet
On electric pressure washers, the filter often connects directly to the garden hose feeding water to the unit. This allows filtering right at the source before entering the system.
Pump Inlet
Filters fitted at the water pump inlet protect right before the high-pressure discharge. This is a common placement for cartridge-style filters.
Frame Mounted
Some gas and industrial pressure washers have filters mounted to the roll cage or engine frame. This allows large cartridge or multi-stage filters to be used.
Filter Micron Ratings
Filter performance is measured in microns. The micron rating indicates the approximate largest particle size that can pass through the filter. Lower micron ratings trap smaller particles. Here are some common pressure washer filter micron sizes:
150 Micron
Most electric pressure washers use 150-micron filters. This traps sand and debris that could damage pumps.
50 Micron
For pumps that require added protection, 50-micron filters are used. They block finer sediment.
5-25 Micron
Heavy-duty cartridge filters often rate from 5 to 25 microns for commercial use. This filters out algae, silt, and even bacteria.
1 Micron
Specialty filters down to 1 micron are sometimes used when filtered, debris-free water is needed for applications like painting or delicate washing.
| Micron Rating | Contaminants Filtered |
|---|---|
| 150 | Sand, grit, pebbles |
| 50 | Sediment, silt |
| 25 | Mold, algae, bacteria |
| 5 | Fine particles, rust |
| 1 | Microscopic particles, paint chips |
Filter Maintenance
Regular filter cleaning and replacement is required to keep a pressure washer operating at peak performance. Here are some filter maintenance tips:
Check and Clean Often
Examine filters before each use and clean as needed. Flush trapped debris by back-flushing with water. Inline filters can often be cleaned and reused while cartridges may need to be replaced periodically.
Use a Filter Cleaner
Specialized pressure washer filter cleaners help dissolve and break down oily residues and mineral deposits from filters to prolong usage. Run the cleaning solution through and rinse thoroughly.
Replace When Damaged
Look for cracked housings, bent fittings, missing gaskets, or other signs of wear. Replace the entire filter assembly as needed to maintain a tight seal and prevent leaks.
Monitor Pressure
A drop in spray pressure indicates a clogged filter that needs service. Delaying cleaning loses performance and risks pump damage.
Check for Leaks
Small leaks around the filter often signal a bad seal or worn gasket. Dripping water also leads to pressure loss. Reinstall or replace components to stop leaks.
Selecting Replacement Filters
When purchasing a new pressure washer filter, check that:
– Micron rating matches OEM filter
– Diameter, length, and connections fit your model
– Housing material suits the application
– Gaskets are included to ensure sealing
Using an incorrectly sized or rated filter risks leaking and failing to protect the pressure washer. Consult the owner’s manual if unsure.
Impacts of a Blocked Filter
It is critical to keep the pressure washer filter maintained, as a blocked filter can lead to the following issues:
Loss of Pressure
A clogged filter restricts water flow to the pump, reducing cleaning power. Pressure can decrease substantially from the pump’s rated PSI.
Pump Damage
Continuing to operate with low pressure due to a blocked filter risks damage to the pump valves, plungers, and seals from cavitation or overheating.
Costly Repairs
Replacing damaged pump components or the entire pump can be expensive. Proper filter maintenance helps avoid these major repairs.
Hose and Accessory Wear
The high-pressure hose and attachments like nozzles wear out faster when run at lower pressures than designed for. Lack of filtering accelerates wear damage.
Reduced Cleaning Efficiency
Insufficient spray pressure leads to longer cleaning times and frustration from a machine not working as expected. Maintaining full pressure is key for cleaning performance.
Safety Tips
Observe these precautions when servicing your pressure washer’s filter:
– Disconnect from the power source before working on an electric pressure washer.
– Release pressure from the pump and hose before filter removal.
– Wear eye protection to avoid spray from pressurized water.
– Check for leaks when reattaching the filter.
– Follow the manufacturer’s instructions for filter replacement.
– Let the filter fully dry before running the pressure washer to avoid water contamination.
Proper handling protects both the user and equipment when maintaining the filter.
Conclusion
The filter on a pressure washer provides vital protection to sensitive components while also optimizing performance. Inspecting and cleaning the filter routinely prevents costly damage from debris ingress and flow restriction. Selecting the appropriate micron rating and replacing worn parts ensures the filter continues effectively sieving water entering the high-pressure pump. Proper filter care prolongs the life of a pressure washer and allows it to operate as designed for superior cleaning results. With a well-maintained filter, your pressure washer can handle the tough jobs without compromise.