Either lower the pressure using an adjustable nozzle. Or by changing the nozzle to one with a larger orifice. Don’t lower the pressure with the unloader. This will cause the pump to be running in bypass. Not good for the pump to be run in bypass for extended periods of time.
Start out with a good distance between the nozzle and your house’s surface. They will remove dirt, and underlying paint, and even wood.
I got mine many years ago. Last year it starting leaking and I was able to replace all the seals and valves. And it runs like a top again.
High pressure will peel paint and could cause damage.
Better to go with high water volume and lower pressure.