I appreciate everyone's interest. I have pictures of my old plumbing setup and new, just don't know how to post them. I am familiar with the concept of boiler operation because I had been running a CB 5640 since 2002. My circulation pump does draw from the top, flows to the house, returns to the bottom. I have many years test lab experience and have some very high quality equipment that I have been using for temperature measurement. The initial thought was the FireStar thermal couple was miss located or maybe bad. CB sent me a new sensor, which I installed. Using my equipment, I checked water temperature in the Firestar TC port, (of course with heat sink compound), and confirmed a 185 temperature. I used the same equipment to measure water temperature at the water level tube. I would drain several quarts of water them insert my TC in the tube, allow water to flow out, and take my reading. 165. This appears to confirm that the water jacket temperature is not uniform across the top of the tank. I first guess was that this condition could be caused by something blocking the convection flow of heated water rising from the heat exchangers, migrating across the top of the tank, with cooler water flowing in the lower portion of the tank toward the heat exchanger side. A simple system that works . . . or should work. For some reason, it doesn't in my furnace, and I am trying to determine why. My guesses have been maybe the water depth across the top is too shallow for the heated water to migrate or maybe blocked. Or maybe the lower flow path may be blocked. There is not much else in the system that can give me what I am seeing. If there is a restriction of some sort (top or bottom), I tried supplementing that designed flow with an additional pump to move water from the cooler, lower part of the tank (using one of the water return ports) and flowing to the heat exchanger side. The only port available on the right side is the water drain which is located on the back, below the heat exchangers. This is something that should not have to be done if the designed natural circulation is there and working. Well, it didn't help. Responding to E Yoder's comment, all I wanted to accomplish was to improve the natural circular flow in the water jacket, right to left on the top (hot water), left to right on the bottom (cool water).
Regarding air in my house circulation, the line has been purged; but it is not really necessary. My lines and heat exchangers are all well below boiler level, but I still regularly purge to be sure no bubbles are restricting flow. But, flow of my heating pipes is not my problem.
I should add, that even when all circulation pumps are off, I observe a huge temperature drop from the FireStar temperature to the water level tube. I do not recall the exact number as the test was done last heating season. I will be doing this again when I fire up the furnace (which may be in the next few days). Something is just not right and I haven't been able to put my hands on it.
I have tried raising the FireStar setpoint from 185 to 195 (a suggestion from my local CB Dealer). Wood consumption rose dramatically, I could hear water boiling above the heat exchangers, and outlet water temperature did rise from 165 to about 173. I ran it for several days, but boiling water is not right. I reset back to 185.
I have talked with both CB and my dealer. Both say this can't happen. Maybe my pump is installed backwards . . . well, it is installed correctly.
ANY IDEAS ARE MUCH APPRECIATED. THANK YOU FOR LISTENING.