I'm sorry I wasn't very clear with my first post. I'm looking at Outdoor Water Boilers, and I am planning on using it as much as possible. (At least in winter, I don't know if it is worth while to run the boiler for the water heater in the summer.) I say that the gas furnace (most likely propane) is the primary, because I don't think I can build or sell a house listing a wood boiler as the primary heat source. I thought the problem was that loading wood daily isn't reliable enough. The bank and county want to see a heat source that doesn't depend on daily manual labor.
Someone sent me a private message about a valve that shuts off boiler flow to the furnace that is controlled by a thermostat. This is the kind of thing I am looking for, but I don't know if there is a single thermostat that can control everything or if I need multiple thermostats. (One set to turn on the propane furnace and control the fan and another that controls the heating valve.) I also don't know if there are variable speed pumps that slow down flow when there is less demand or if there is a bypass that kicks in when the heating valve is closed.
What I would like to know is if there is a source that has multiple plumbing designs and even better if it discusses pros and cons of the designs.
I know that some people heat garages, work shops and even sometimes driveways to melt snow, and I will probably consider doing that as well, I just don't know what is available for controls and how it gets set up .
Thanks for the help.