I have its twin, its a Burham SFB wood/coal boiler. I live in far colder area in Northern NH near the Canadian border and Berlin NH which frequently sets low temp records in New England. If you get down on the floor and look up at the grate through the ash pit, it should have a coal grate and a rotary shaker. I got mine used and this assembly came in several damaged pieces. IMHO, it was really a coal boiler design converted for wood.
A friend welded up a fixed grate and that is how I use it. (I just burned the grate out after close to 20 years) Mine was poorly installed in its original home (I got it for free). I started from scratch and redid the controls but the originals are pretty simple. I think I have a copy of a manual for it or at least for a similar boiler. I cannot see the left side in your photos. There should be a second relief valve set at 12 psi that dumps water in the firebox if the mechanical safeties do not work. IMO it is a "tank" vastly overbuilt but as noted, it is not a super-efficient design.
The odd thing is mine had a similar sooted out front panel above the loading door. Its flue was reduced down from 8" to 6" and then into a wye fitting with an oil burner vent on a short stack so it had draft issues. Mine did not have a barometric damper and I would consider removing it from yours if it has draft issues. Alternatively, you could cover it tightly with foil and see how it runs once you get it hooked up. I ended up taking the front panel off, givint it light sand and sprayed it with similar blue color. I have a bit of soot stain but nothing like it was. My temp pressure gauge was slightly melted but still works.
The bad news is without thermal storage it can be a "smoke dragon" and creosote producer, very similar to an outdoor wood boiler. If you look inside at the top of the fire box there should be 4 steel baffles diverting flames towards the front of the firebox. I do not know what Burnham made them out of but standard steel plate only lasts 3 or 4 weeks in heavy heating season before they droop down and fall out. I just pull them out and bend them back until they get too thin. I get a batch made up at local steel supply place every couple of years. I think a lot of folks removed them. They improve efficiency. When I first got it, I hooked it through the oil boiler and locked out the oil burner gun while using the oil boiler controls to run the zones. I only used it in very cold weather or when I was away for the weekend with the temperature set back to warm the place up.
The fundamental problem with this design (there were several different suppliers of simialr equipment) is when run on wood, it is set up to burn full bore or nothing. As long as you are pulling the heat away from it, its fine but once you stop pulling heat away, it quickly heats up and shuts the air damper down. The aquastat on the left is the control for the motorized air damper on the left. The chain is hooked to the lower air damper door. The lower damper door is not air tight and there is the hole in it so it does not go out but it does smoulder and puts out a dark plume of CO containing gases and potentially creosote up the stack. Once there is a call for heat the damper opens back up again. If the air damper closing does not work, the aquastat on the right opens a overheat valve that either goes to a dedicated dump loop or radiator or it bypasses any zone valves and goes to one of the house loops. If that does not work (usually because someone is running it with the lower ash pit door open bypassing the air damper control), then the 12 psi safety relief valve opens and sprays water on the fire to put it out (and makes a mess) and then finally a standard 15 psi pressure relief valve will dump to the floor. BTW because its a bottom grate design you can get away with running less than perfectly seasoned wood. Since it runs hot, the creosote usually stays hot enough to make it out the stack before condensing That means a lot of heat is running up the stack but that is the trade off.
I do not see an expansion tank, the boiler holds a lot of water and a typical household tank is too small. I have two standard sized tanks but a jumbo tank is better. If you do not have enough expansion volume the water will find a way of leaking out, usually via a relief valve but sometimes a pump gasket.
So for a couple of years I used it without storage on weekends and cold evenings. I cut my oil use compated to my prior Fisher with far better heat distribution but it was too much hassle for most folks. I still was using oil at that point. After 3 years, I installed storage and stopped using oil entirely. I have 500 gallons of storage in an American Solar Technics vented versus pressurized tank. There are pros and cons to the two types of tanks but in my case I could not get a 500 gallon propane tank in my basement while I could easily assemble an AST tank. The AST tanks are rectangular versus round so they take up less room. There are rumors that the owner of AST is selling out, he is member of Hearth.com but drop him an email at his website to get the story. Tarm in Lyme NH also sells various tanks. I have not really used oil for 6 years. I just heat up the tank for about 1 to 2 hours at night and then run the heat for the house off the tank. Ideally, I wish I had bigger tank as in cold weather it means an evening burn and a morning burn. I have about 1500 square feet of heating space (a floor and half) and use 3 1/2 to 4 cords a year (my house is tighter than most). I heat my hot water via am Amtrol hot water maker to about 180 degrees and that carry's me for a couple of days. I have solar hot water for 9 months a year so I only need to heat hot water when running the boiler. Note I also have slant fin, if I went with low temp emitters in place of the slant fin, I could run my storage down to much lowet temp which would effectively raise the storage tank BTU capacity but its not worth it as my wood is for free.
BTW, the original design was that the circulator pump ran 24/7 as long as the boiler had power, if it was not piped correctly this could cool down the oil boiler and cause it to run. I added an aquastat on the pump so that it does not run until the wood boiler is140 F. It also is tied to my oil boiler burner gun so the oil boiler will not run if the wood boiler is hot. I have complex relay based control system I designed from scratch to coordinate heating up the storage tank and making sure I do not overheat it. It also runs the heating system to pull heat out of the storage tank and use the existing Tstats and zone pumps to distribute the heat. The tricky part is if I turn the power off the wood boiler, everything automatically reverts to the oil system so that if a tech ever need to get the heating system running the wood system is completely transparent.
A flaw with the design is the overheat valve and circuit requires power to open which is useless in a power outage. The air damper will still close and the relief valves will still lift but modern designs have a valve that is normally open and held closed when the power is on. The stock Honeywell valve could be swapped with fail open valve and a relay.
So you have good start but to do it right with storage makes it better and then you can keep an eye out for a good deal on a gasifier to gain efficiency. If you can get it up and running and you are willing to be a "boiler slave" you can save some oil in colder weather.
I just picked up a Tarm solo 40 gasifier. It is larger heat output, I could replace the Burnham but odds are the Tarm will go in a new house.
