What size piping is on the IDW loop? What is the head loss of the boiler? Looks like you have 3 007's in there, whose IDW tank is that? Piping work looks good. Can't see the expansion tank. Doesn't appear that your pumping away. It appears that the IDW pump is too small and possibly the others depending on the head loss for those zones. What size solo is it?
I really appreciate the nice work, but all that can be for naught. A simple reading of the manual will tell you the recommended way of near boiler piping and thats not it. Also the head loss of the solo says the 007 is too small unless that is a 60k unit. I would like to know the heater brand because I'm pretty sure its supposed to have 1" piping ( even tho the tappings are 3/4) and calls for a larger pump, even tho the solo has a better head loss than other mod cons.