Outdoor Power Equipment and Small Engines - Pressure washer

I purchased a power washer 4 years ago. Every spring when I use it for the first time, I press the trigger & there is no pressure.

Each time I take it in for service, they replace the unloader kit. What purpose does this kit serve?

and is there something I am doing wrong to cause this problem?

My previous power washer was 10 years old & I never experienced this problem.

The unloader valve basically keeps your hose and other fittings from being blown out from pump pressure when you are NOT depressing the trigger.
I think most manufactures recomend not letting the unit run idle for longer than 5 min. Personally I think that an extremely long time never the less...
Also proper storage between use and seasons. As well as hourly maintenance recomended in the Owners Manual.

Also a Simple and sad fact, the push to produce more for less has left quality assurance unchecked. More often now than ever mass runs of produced items may have or be defective.

Azis said the most in his last statement. You could run some pump conditioner through it before storage. Better yet, you could remove the unloader before storage and coat it with oil or vaseline so that it will be protected and ready for next year.

Thanks for your input. I will proceed with your suggestions.