Richard@PM
ArboristSite Member
Ok here we go, you have radiant with no indoor boiler,first get a good cold start boiler ( I like the Biasi direct vent ), replumb the lines from the wood boiler through a plate exchanger ( with counter current flow for best heat exchange ) on the incoming wood boiler side place a honeywell strap on aquastat to the copper or black iron piping ( pex will not work well ), use the r and b terminals to interupt the power to the b-1 terminal wire that fires the oil burner, set the strap on aquastat at about 160 degrees, any time that the water temp coming in from the wood boiler is above 160 degrees the oil boiler cannot fire, below 160 the oil boiler will fire on any call for heat and it will run up to its setpoint of 185 degrees, now you will have two sources of heat protecting both wood boiler water temps and home heat. Next lets look at the oil boiler side, this should be piped in a primary secondary manner so that the oil burner is not heated by the wood boiler when it is not needed, only the primary loop that supplies your radiant will be heated at this point and your radiant loops draw from it, the oil boiler then injects into that loop only when needed. When piping this primary loop you should install two more tees and ball valves for any future alternative heat sources or extra loads and just cap them off. If this sounds like something that you are interested in getting involved you may PM me and I can explain in more detail over the phone. I still type with one finger and have not yet figured out how to post photos from my phone on here, perhaps someone could help me with that part and I can post a diagram of this setup.