QA

Question: Pressure Washer Shuts Off When Trigger Is Released

If a pressure washer stalls when the trigger is released, this usually indicates a fault in the unloader valve. It is a simple process to remove and replace the unloader.

What happens if unloader valve is bad?

A failed unloader valve can cause high pressure at the nozzle. The unloader valve recirculates water to the pump inlet when the pump is running but the spray wand isn’t in use. A defective pressure regulator can cause high pressure at the nozzle.

What does the unloader valve do on a pressure washer?

The unloader diverts the flow of water from the outlet side of the pump back to the inlet side, causing water to flow in a loop back to the pump under virtually no pressure rather than to the nozzle under operating pressure.

How do I know if my pressure washer unloader is bad?

Water leaks and inconsistent behavior are also signs of a potential failure in the near future. González: The typical signal when there is an unloader malfunction is a reduction of flow through the nozzle, which results in pressure loss. Dean: Typical symptom of an unloader failure is a sudden smooth pressure loss.

How do you diagnose a bad unloader valve?

Pump motor stalling – if a pump is powered by a gasoline or diesel engine, stalling whenever the operator ceases to use it is a good sign of unloader valve failure. The buildup of pressure locks the pump’s internal components, which in turn prevents the rotation of the powered engine shaft.

How do you unstick a unloader valve?

How to Remove the Pressure Washer Unloader Valve Install a high-pressure tip on the pressure washer. Locate the nut located on the top of the unloader valve. Turn the pressure adjusting knob in a counterclockwise direction until it is completely removed.

Do all pressure washers have an unloader valve?

Power washers that have a trigger gun control on them most likely have an unloader or bypass valve.

What is a trapped pressure unloader?

A trapped pressure unloader is a simple valve with a spring mechanism mounted in a Brass body. There is A channel within the body that gives water access to the back of a piston. When the trigger is released the pressure against the piston increases and pushes the spring open to allow the water to pass into the bypass.

Why does my pressure washer keep losing pressure?

Pressure may decrease if your packing is worn out or if there are abrasives or severe cavitation (bubbles) in the pumped fluids. This can be caused by an inadequate amount of water and/or a lack of proper filtration. To fix, install the proper filter.

How do I know if my pressure washer wand is bad?

Several indicators will show a faulty pressure washer pump. The most common is a leak, pulsating output pressure, and low output pressure. Leaks are often caused by a worn or damaged pump seal. A pulsating pressure indicates that there is not enough water in the pump.

Can you adjust an unloader valve?

Now while the gun is engaged you can adjust the pressure by turning the adjusting knob between the two nuts and the nylock on top. If you adjust the unloader without the gun engaged, when you do engage the trigger parts in the unloader move rather violently and could damage the unloader.

Why is my pressure washer pulsing?

Why is my pressure washer surging? Water flow may be restricted to the pressure washer. Check that all hoses are free of kinks, leaks, or blockage. If the nozzle has even a little bit of dirt in the tip, it may cause enough obstruction for the pressure washer to pulsate.

Is it OK to run pressure washer without water?

Although you can start a pressure washer without water, it is not advisable to do it. The water helps to lubricate the pump and help to keep it cool. Without the lubrication and cooling properties of the water, dry starting will cause the pump to wear down quickly.

Do you turn the water on before you start a pressure washer?

It should not be hooked to a potable water source. Turn on the water. The pressure washer hose will fill with water, so it is important to purge the system of excess air before starting the unit. Simply squeeze the trigger on the gun and the air will release.

How does an unloading valve work?

Unloading valves are pressure-control devices that are used to dump excess fluid to tank at little or no pressure. A common application is in hi-lo pump circuits where two pumps move an actuator at high speed and low pressure, the circuit then shifts to a single pump providing high pressure to perform work.

Why does my Karcher pressure washer keep losing pressure?

A loss of pressure can be caused by a number of things. – Make sure your garden hose and high pressure hose are not kinked, leaking, or blocked in anyway and that the water is turned on full force and supplying the correct amount of water outlined in your owner’s manual.

What is unloader valve?

An air compressor unloader valve is a device used by air compressors to release the trapped air inside the compression chamber and tank discharge line when the motor stops. Extracting the air by the unloader valve is essential for the compressor motor to start again without any effort.