Definitely. The section in the manual about adjusting is poorly written, though. In just a couple of sentences the writing leaves a lot to interpretation, but the bottom line seems to be this: Adjust the pressure switch until the pump runs (faucets all off); back off the adjustment until the pump stops, then back off another 1/4 turn.
My wife is going to love the amount of water being delivered in the shower, now!
Yes, it is an Atwood water heater, but there is no mixing valve that I can see. Long ago, back in 1976, I used to live in Magnolia, Delaware. I worked at C&L Electronics which used to be on the corner of Main (State Street in Dover) and Walnut Street.