What Causes My Pressure Washer To Lose Pressure?
There are some of the most common reasons a pressure washer may start producing lower water pressure over time. You might think it comes from internal components that are difficult to repair and replace. But for the common, it comes down to the simplest parts you can access.
According to our statistics that the popular reasons are from the hose, nozzle, filter, and unloader valves.
Clogged Inlet Filter
The inlet filter is blocked or clogged by dust and garbage particles in the water you use, causing the water supply to be insufficient, resulting in insufficient pressure.
Incorrect & Damaged Hose
A kinked, cracked, or clogged garden hose is one of the easiest and most likely causes of low pressure in a pressure washer. Since the hose provides the water supply to the pump, any restriction immediately limits how much pressure the pump can generate. So always start by thoroughly inspecting and testing the hose whenever you experience low pressure!
Worn Belt
A belt transmits power from the engine to the pump. If this belt slips, it cannot spin the pump fast enough to generate high pressure. Belts can loosen over time due to stretching, wear, and vibration. This causes the belt to slip on the pulleys, reducing pump RPM and thus water pressure.
To tighten the belt:
Loosen the idler pulley bolt or adjuster screw
Use a wrench or screwdriver to rotate the idler pulley to increase tension on the belt
Retighten the bolt or screw to secure the idler pulley in place
Check that the belt still has some flexibility and is not overly tight
To replace the belt:
Loosen and remove the idler pulley
Remove the old belt
Measure the belt length and width required
Purchase a new belt of the same specifications
Install the new belt and reassemble the idler pulley
With a new belt properly tightened, the pump should be able to spin at full RPM again, restoring water pressure.
Unloader Adjustments
The unloader valve is a safety valve designed to relieve excess pressure generated by the pump. It also helps control the pump's maximum pressure output. Adjusting the unloader valve slowly in small increments while the machine is running can often help increase water pressure, either as a temporary or permanent fix depending on the valve's condition. The key is to adjust the valve the correct way while the pressure washer is running.
Blocked Nozzle
A blocked nozzle will prevent water from escaping properly, creating back pressure that keeps the pump from generating its full pressure. Always ensure your nozzle is clear of debris and obstructions. Worn nozzles allow it to escape too easily, lowering pressure over time.
Pressure Washer Loses Pressure After a Few Seconds – Tips to Prevent
1. Use a fresh, clean water supply
Using dirty or sediment-laden water can quickly clog the inlet filter and valves, reducing pressure. Whenever possible, use clean tap or well water.
2. Clean the water inlet filter regularly
This is the first line of defense against debris that can clog the pump. Clean the filter after every use or at least monthly to maintain optimal water flow.
3. Inspect and replace hoses as needed
Make sure the inlet and high-pressure hoses are in good condition without kinks, leaks, or cracks. Replace hoses every 2-3 years to avoid flow restrictions.
4. Lubricate moving parts regularly
Properly lubricate the piston rods, valves, and O-rings to prevent wear that can cause internal leaks. Follow the manufacturer's lubrication recommendations.
5. Avoid running the pump dry
Only operate the pressure washer when there is a steady flow of water. Running the pump dry can damage valves, seals, and other parts.
6. Check belt tension
Ensure the belt driving the pump is properly tightened to avoid slipping, which wears out the belt faster and reduces pressure. Adjust belt tension as needed.
7. Use the correct nozzle size
Using too large of a nozzle for the pressure washer's output wastes pressure. Choose the correct nozzle size for the job and the pressure washer's maximum PSI.
8. Avoid prolonged storage
If storing the pressure washer for more than a month, follow the manufacturer's recommendations to prepare it and prevent parts from seizing.
Regular maintenance and following the manufacturer's guidelines are key to keeping your pressure washer in top condition and operating with full pressure for as long as possible. Proper care can significantly extend the life and performance of your machine.
