Identifying and utilising a Jensen boiler

As several recent threads of mine have tipped off, it's looking like an expensive winter for heat. So I have begrudgingly cleaned out the wood boiler downstairs and have begun to test it out.

All I can figure out is that it's a Jensen that doesn't appear to burn coal. It doesn't have shaker grates at least. 

I burned some cardboard in it and didn't get any smoke in the house, so I'll say that the exhaust portion is in good shape. I then built a small wood fire in it and I'm seeing how that goes.

This thing came with the house, no documentation, no manual controls aside from the door and ash door, and a flippy thing in the chimney. 

Installation looks staggered in series with the oil burner. Like the water goes through the oil burner, then through the wood burner, then to the rest of the house. Except for one 2 inch pipe that comes out of the top of the oil boiler and good towards the house but is also tied to where the water taps from the main and goes to the overflow tank? I can't get a picture that doesn't make that description even more confusing. 

I don't know anything about this other than I built a fire in it and saw smoke coming out of the chimney outside.

I've been hunting around for forums and keep finding "search noob" or combination coal units that everybody packs fill with coal and brags about how many hours they get.

I'm just trying to get an idea on how big of a fire I need, how much attention it needs.

Mainly I want to use it at night to cut down on oil usage when the ambient temp is lowest and nobody is moving around or cooking making more heat. But not if that means I have to go down and stir the fire every hour or two. 

I hate wood burners with a passion. I have nowhere to store dry wood, but there's a lot of dead stuff around the house and a lot of old rotten stuff I feel better about burning because it's not in our living space. 

Is this a fools errand to only run it at night? Is there a good resource out there anywhere? Jensen is apparently known for not putting model numbers on any of their products, which makes looking for manuals a bit more difficult.

The sub plan is to save all the kids papers and all our boxes and E36 M3 then next summer spend a few days making fire bricks out of it all if I can make room to store them where they'll stay dry once their dry. 

My uncle and one of my best good friends both have a similar system and for what it is - it works well.  Its a lot more maintenance intensive than the newer automated units, but they are cheap to run if you have a limitless source of wood.

Since you dont know the age of it, the instructions, or the condition, I would consider it "money well spent" to have an HVAC professional look it over, make sure its safe, and give you a rundown on how to run it.   Something about boiling water, wood fires in my basement, and uncertainty make me pretty nervous.  

In reply to 93gsxturbo :

I should probably call the guy that installed it back again. Well, I should say the guy who installed the oil boiler in 96. I know the previous owner hated the oil burner and used wood until 2018 or so when the series of injuries that led to them selling the house started. 

Instead I started a small fire in it before I made the first post. 2 hours later, meaning 15 minus ago I restarted it with some bigger pieces and I'm just going to check on it every hour. 

I think the big test is going to be tonight. Planning to just fill it up around 8 and leave it alone until morning. I can usually hear the oil burner when I get up in the middle of the night, so I'll just listen for it. 

Condition is solid, inside and out, except for the grate. Some gauges are really clouded over, but without playing with or adjusting anything I have no leaks I can see. I know, won't smell or see CO, but the garage is downstairs, and the boilers are surrounded top bottom and 3 sides by concrete walls. The chimneys (I'm calling them chimney because I don't know what else to call them, duct work from the output to outside) appear similar in age and go to a comically tall exterior traditional chimney. The garage doors also leak, a lot, so I've previously sealed around the doors between garage and living space, and any gaps after a mouse invasion last year. 

I'm still trying to figure out why they put in, or rather, sealed off a fireplace in the living room to use the downstairs heat. Not that I have space to store pellets, but if it wasn't sealed off I would have bought an insert last year and found room for pellets. 

Read over your homeowners insurance that you might need to have it formally inspected to operate.

My dad had a house with a wood/oil boiler. When he moved into the place it was fall and a bit chilly so he had me burn all of the moving boxes. I fired those boxes into the thing keeping it as full as possible. Next thing we knew the house was well over 90*.

x2 on getting it inspected.

I can't help with the Jenson, but they probably sealed off the fire place in the living room because an old-style fireplace is something like -190% efficient.  I'm not even joking, they'll make the room they're in warmer, but every other room in the house cooler.