Rob R. wrote:It probably had a B&G series 100 circulator, which has a very flat pump curve. If you put a high head circulator on the return of a system with lots of resistance to flow, it is possible to have serious air problems and/or cavitation.
B&G used to have a great video that demonstrated this...too bad I can't find it.
That's why I installed the circulator on the return side on the EFM. The house I grew up in had an American Radiator/Standard Sanitary gas boiler in it, one zone, cast iron radiators, and a B&G series 100 circulator on the return side. I figured that's the way it's done, but I understand the reasons for plumbing it differently.
With regard to the Taco air scoop, I understand the reason for having a straight run of pipe on the inlet and the outlet, in my installation I didn't have enough room, so I chose to have the straight run on the inlet side. So far it seems to be working fine. If I had the space I definitely would have straight runs on either side.http://nepacrossroads.com/download/file ... &mode=view
It's not perfect I admit, but it seems to work reasonably well.