Oil boiler with wood add on question

[Justin1972]

Hello new to the forum, I know this has been probably beaten to death but could some of the boiler guru's take a look at my set up. This is the system I have been running for about the last 15 years it is how it was set up in the house when I bought it. It works but probably not the most efficient system. My oil boiler is leaking so I have purchased a new to me boiler that is 7 or 8 years old in very good shape. I am going to install it but was wondering if I should plumb it in differently to make it more efficient. I have the oil burner on a switch that shuts the burner off and I burn mostly wood. I found the oil came on to much ($$$$). I have one zone valve and one circulator. Wood is set to turn on circulator and open zone valve if temp goes above 220, that's my dump. Only problem during power failures have to manually open zone valve. Oil furnace is shut off during off season running electric HW heater. Domestic HW is piped through Wood then Oil to Electric all year with boiler shut down. I guess the main furnace would be oil boiler with the add on wood, just I keep the burner shut off most of time, 95%. Oil is set to 160/180 wood damper set to 200 degrees. Have an old 2 story farm house very little insulation new windows though 1600 square feet, burn 7 chords wood about 50 gallons oil.
Any Advice?

 

[maple1]

Couple quickies:

-On the DHW thing, if you turn off the oil in the summer you don't gain anything running it thru the oil burner. And in periods of non-use (like if away for the weekend or something), the DHW tank will cool off some & the elements will likely kick in before the incoming water from the boilers gets it hot again. So you might think about adding an HX that will heat the whole DHW tank & keep it hot whenever the wood fire is burning no matter how much DHW is or isn't being used. A sidearm HX would likely work for that with the right arrangement with no added pumps needed.

-You could maybe run the boilers in series (wood-oil-system) and get rid of the manual valve operation aspect - although there might be a little bit of efficiency hit. You might also be able to accomplish the same thing without going full series layout - like maybe a primary/secondary setup. Maybe others can add input there.

-The dumping could be improved by using a normally open zone valve, that would open naturally in a power outage. But you would need to change the controlling of it up by using an aquastat/controller that breaks on rise rather than makes on rise (supplies power at low temp, cuts it when temp reaches setpoint/200f).

EDIT: Definitely not a guru here...

 

[velvetfoot]

I am also definitely not a guru either, but doesn't the piping diagram show flow always going through the oil boiler?
Would the parallel setup with check valves and with a circ. pump for each boiler be better? Or maybe in series like maple opined?

 

[Justin1972]

,The way it is set up it with only one circulator and the burner shut off, it is always circulating through both furnaces. I always wondered how much heat loss I was getting heating both furnaces with only wood. I had a system in another house that I used to own that had a circulator between the furnaces and one on the return line. The way this is set up when I 'm not calling for heat and I am below 220 water doesn't circulate and the oil furnace water will cool down. as far as DHW I mostly heat with electric HW heater, except in the winter I preheat the water through the boiler, but this sometimes cools the boiler down, I run all domestic HW through the furnace even in summer when the furnace is shut down. This maybe causing the furnace to condensate as well. Any how to's on a side arm? Never had anything to do with them, not really sure how they work.
Wouldn't my set up be in series if I turned the burner on? The way I run it now the oil burner is shut off, usually in the morning I turn on the oil let the burner cycle a couple times, then shut it off, just to bring boilers up to temp. My wood boiler is a NY 100 a bit small for the house, I was wondering if she works to hard to heat both furnace on it's own, and if there was another way to hook it up so it doesn't have so much water to heat?
Anyone have any diagrams of a set up that might work better for me (with out breaking he bank).