Welcome! Here are the website rules, as well as some tips for using this forum.
Just wondering if any of you experts out there have ever had a problem like this and if so how did you solve it. Our company installed a new oil fired boiler for a customer. There were 6 zones using circulators on the return side of the boiler. The customer had an outdoor woodstove so we piped the heat exchanger in series on the return side between the circulators and the boiler. We also installed a system circulator between the heat exchanger and the boiler. That circulator runs whenever any zone circulator is running. The boiler maintains 175 degrees just fine. The problem is that when all 6 zones are running we lose flow in many of the zones if not all. There were 6 taco 007 circulators in the system. We replaced them to Grundfoss 3 speed circulators and that did not improve the situation. I was thinking about putting in a variable speed circulator for the system circulator and put in zone valves. Could we be over pumping. The zones are all 3/4" and the main header is 1 1/4". We are talking about a small 3000 sq ft house. Any ideas??