Wood – do if the wood boiler keeps tripping the high limit switch

You need someone that knows exactly how the near-boiler piping should be. Even a slight change in the diameter, the height above the water line, or the return system will affect the system's operation.

Also, on a one pipe steam system, the maximum steam pressure should not exceed 3 psig. The output of the new boiler should exceed the connected piping and radiation load by about 33%. On a steam system the boiler size is dictated by the connected load and not the heat loss of the building.

All radiator valves on a 1 pipe steam system are only for isolation of that radiator and need to be fully open or fully closed; no partially open/closed steam valves. Steam vent choice is also critical. Again, I say again, you need someone who knows steam piping and most people in the business do not!!! I rattled on about piping and etc. and forgot to answer the original question. Yes you can use baseboard radiation on a one pipe steam system. the minimum pipe/radiation size is inch and 1/4 if a short run or preferable 2".

If the bottom floor is radiant in the floor heat then you have a thermostat for that zone only. The thermostat is a Model T87 by Honeywell. Also in this zone there should be a thermostatic valve controlling the water temperature to the slab (floor). I would look for a zone valve for this system. If you can't trouble shoot this your self I would call an HVAC co. to do the work so you don't do something you can't fix.