I have a prochem performer with a a12 nissan, I wanted to know if you have to attach your heat bypass lines to the waste tank or can you attach them to the fresh water tank so your not wasting water?
It can be done. The only problems I see with that are, if your tank starts to run low, you will be using super heated water for the intake(not good). And if your diaphram has a hole or worn you pump chem into the tank. That could throw off proper chemical on a larger scale.
What about the relief on the water box does the waste tank act like a vacuum and pull the water from it, or does it just flow on its own?
the relief valve is vacuum activated so it has to be left attached to the waste tank...the bypass can be ran to the water tank, I have done this, works really well to preheat your water...when you get to a job fire up and turn your temp gauge all the way down so it is constantly cycling the water through, then adjust when you are ready to clean...I was getting a 10-15 degree increase off a 100 gallon fresh water tank...as noted above make sure you have enough water in fresh tank, you don't want to be sending 180 degree water into machine, although the relief valve will still protect you somewhat...
I hooked up my bypass to the fresh water tank and it seems to be working great so far. No more wasting water into my waste tank.