slabadie wrote:I do have a dump zone (set at 220 degrees), but I beleive the zone is too small.
I'd cut that down, try something ~195 or even 190. By the time you hit 220 you've got a lot of heat to dump. Yes, the dump zone should be the largest zone in the system. The temp will somewhat depend on what your setup requires for water temp
My overheat is set at 180, 7 degree differential. The thermostatic damper control adjusted so it just closes fully when the water temp hits ~170. It's balanced fairly well - only hits the overheat if the damper door is closing after a hard burn.
slabadie wrote:There is one issue that I have and I think that one of the ball shuts should be closed because it looks like I am re-heating already heated water. If I can ever get the plumber to call me back, this is something for him to look at as well as repairing some leaks with his soldering.
You may be referring to the bypass loop. This is normal (and correct) install so that water circulates between the two boilers even when there is no call for heat. This allows the oil boiler to act as heat storage for a faster response to a call for heat AND to prevent boiling the water in the coal boiler.
The bypass valve should be partly closed. "Water is lazy" and will take the path of least resistance. If the bypass loop is "easier" it will go there instead of your heating zones.
Eeek, leaks not good news. Given that and his calling your oil boiler "unrepairable" you might want to get a 2nd opinion.
Got any pictures of the install?