The end of last season turned into a nightmare at best. Over heating issues led to cavitation issues. I couldn't get enough heat out of my boiler to save it from going into idle mode, No matter what I did. Some of you may remember my threads on over heating and cavitation from last year. So fast forward to now. I've made many changes. Cut my head losses by more than half, went to a bigger FPHX, and went to induced draft. I went back in my old thread to try to find my head loss numbers on both sides of my old FPHX but could only find the boiler side. Last year I was running almost 20ft of head on the boiler side. This year I've cut that side down to less than 5ft. My storage side this year is going to be about 14ft and both sides I did the math based on 10 gpm. Pictures... FPHX old vs. new Storage side plumbing old vs new Boiler side plumbing old vs new Induced draft setup I still need to add length to this pipe to get it up in the flue a little more. I still need to tidy up the wiring, it's all hooked up for testing purposes at the moment. I need to put another piece of foam over the front of my FPHX and a cover plate. Planning on firing it up soon, hopefully things run alittle better now.