Rob R. wrote:I don't have nearly the experience of other folks in this business, so take or leave my advice. With that said, I just finished a coal boiler install on a system that has baseboard, radiators, and a big radiant system. I piped it like this:
The diagram doesn't show the mixing valve for the radiant zone, but you get the idea (ignore the pipe sizes and such on the drawing, I just picked it as an example). The primary circulator turns on and off as needed to keep the boiler at 145F or above, meanwhile the zone circulators keep on running. The boiler never gets slammed into condensing temperatures, the circulators serving the zones don't need to turn on and off to protect the boiler, and there is enough flow in the primary loop to prevent a huge delta between the supply and return. It runs beautifully and the home is very comfortable. It always depends...but that works for me. Just food for thought.
Rob, that is essentially my setup, just replace the ET with the OB and that's how I'm plumbed.
If you take off a line from the arrow on the top of your boiler, and return it just after the seperator, that's how my boilermate is hooked up.
So I'm going to move the feed and return to the boiler mate just like you have the feed and return to the zones and see if that fixes the problem.
One more thing.
Do you think it would be a good idea to make my feed and return line for the zones on the line going INTO the OB? I would think that that would end up using the OB as a huge tempering system to reduce the shock of the cold water returning to the WL110.....