Here are some pics of my setup I just got finished installing. I have a few bugs to work out, but it's working well so far.
I have this setup in my detached garage with 1" pex lines run underground to my house to a "water to air" heat exchanger in my ductwork of my existing forced air furnace. I added a second thermostat in the house, wired directly to the furnace blower only and a strap on aquastat wired in series. So when the thermostat calls for heat, if the boiler isn't up to temp it won't turn the fan on and blow cold air around. I just keep my old thermostat (for the forced air furnace) at a lower temp as a backup.
As you can see I also have a small hydronic shop heater that I put in the garage, I have it hooked up to a thermostat, but only run it when I'm out there because the garage is uninsulated. I just let the hot water run through the loop 24/7 to keep it from freezing (the fan is controlled by the thermostat).
I found the Triad Boiler, and Clean Burn "CB4000" on craigslist. I was going to convert a normal boiler with the CK Burner kit, but luckily found this and saved a bunch of time. I have some bugs to work out on the burner itself, but it's working pretty well considering I haven't put any money into it yet.
I also have to figure out how to clean the boiler better, the previous owner hadn't cleaned it in a while and the fire tubes were almost clogged with soot buildup. I've got them all clear, but the bottom blast chamber still needs a lot of cleaning and the burner is running a lot more that it should be, when the blower is on in the house it can't quite keep up and looses ground on temperature. The burner is probably running 75% of the time, and at that rate I think I'm burning through about 20 gallons/ day to heat a 1200sf house.
As you can see, I have two tote tanks setup. One is for settling, and the other is the tank that it draws from. I have a cleanable screen filter, and a hydraulic filter that it runs through before going into the draw tank, plus the actual filter on the burner pump.
Austin